Selenoproteins play important roles in antioxidant mechanisms, and are thus hypothesised to have some involvement in the pathology of certain types of dementia. Mild cognitive impairment (MCI) and Alzheimer's disease (AD) are both thought to involve impaired biological activity of certain selenoproteins. Previously, supplementation with a selenium-rich Brazil nut (Bertholletia excelsa) has shown potential in reducing cognitive decline in MCI patients, and could prove to be a safe and effective nutritional approach early in the disease process to slow decline. Here, we have conducted a pilot study that examined the effects of a range of single nucleotidepolymorphisms (SNPs) in genes encoding the selenoproteins glutathione peroxidase (GPX1) and selenoprotein P (SEPP) in response to selenium supplementation via dietary Brazil nuts, including selenium status, oxidative stress parameters and GPX1 and SEPP gene expression. Our data suggest that GPX1 Pro198Leu rs1050450 genotypes may differentially affect the selenium status and GPx activity. Moreover, rs7579 and rs3877899 SNPs in SEPP gene, as well as GPX1 rs1050450 genotypes can influence the expression of GPX1 and SEPP mRNA in response to Brazil nuts intake. This small study gives cause for larger investigations into the role of these SNPs in both the selenium status and response to selenium dietary intake, especially in chronic degenerative conditions like MCI and AD. PMID:26661784

I want to discuss both the Single NucleotidePolymorphism (SNP) Consortium and the Human Genome Project. I am afraid most of my presentation will be thin on law and possibly too high on rhetoric. Having been engaged in a personal and direct way with these issues as a trained scientist, I find it quite difficult to be always as objective as I ought to be.

Abstract Osteoarthritis (OA) is a complex disorder characterized by degenerative articular cartilage and is largely attributed to genetic risk factors. Single nucleotidepolymorphisms (SNPs) are common DNA variants that have shown promising and efficiency, compared with positional cloning, to map candidate genes of complex diseases, including OA. In this study, we aim to provide an overview of multiple SNPs from a number of genes that have recently been linked to OA susceptibility. We also performed a comprehensive meta-analysis to evaluate the association of SNP rs7639618 of double von Willebrand factor A domains (DVWA) gene with OA susceptibility. A systematic search of studies on the association of SNPs with susceptibility to OA was conducted in PubMed and Google scholar. Studies subjected to meta-analysis include human and case-control studies that met the Hardy–Weinberg equilibrium model and provide sufficient data to calculate an odds ratio (OR). A total of 9500 OA cases and 9365 controls in 7 case-control studies relating to SNP rs7639618 were included in this study and the ORs with 95% confidence intervals (CIs) were calculated. Over 50 SNPs from different genes have been shown to be associated with either hip (23), or knee (20), or both (13) OA. The ORs of these SNPs for OA and the subtypes are not consistent. As to SNP rs7639618 of DVWA, increased knee OA risk was observed in all genetic models analyzed. Specifically, people from Asian with G-allele showed significantly increased risk of knee OA (A versus G: OR = 1.28, 95% CI 1.13–1.46; AA versus GG: OR = 1.60, 95% CI 1.25–2.05; GA versus GG: OR = 1.31, 95% CI 1.18–1.44; AA versus GA+GG: OR = 1.34, 95% CI 1.12–1.61; AA+GA versus GG: OR = 1.40, 95% CI 1.19–1.64), but not in Caucasians or with hip OA. Our results suggest that multiple SNPs play different roles in the pathogenesis of OA and its subtypes; SNP rs7639618 of DVWA gene is associated with a significantly increased

Genome-wide association studies have proven to be highly effective at defining relationships between single nucleotidepolymorphisms (SNPs) and clinical phenotypes in complex diseases. Establishing a mechanistic link between a noncoding SNP and the clinical outcome is a significant hurdle in translating associations into biological insight. We demonstrate an approach to assess the functional context of a diabetic nephropathy (DN)-associated SNP located in the promoter region of the gene FRMD3. The approach integrates pathway analyses with transcriptional regulatory pattern-based promoter modeling and allows the identification of a transcriptional framework affected by the DN-associated SNP in the FRMD3 promoter. This framework provides a testable hypothesis for mechanisms of genomic variation and transcriptional regulation in the context of DN. Our model proposes a possible transcriptional link through which the polymorphism in the FRMD3 promoter could influence transcriptional regulation within the bone morphogenetic protein (BMP)-signaling pathway. These findings provide the rationale to interrogate the biological link between FRMD3 and the BMP pathway and serve as an example of functional genomics-based hypothesis generation. PMID:23434934

Single nucleotidepolymorphisms have become an important type of marker for commercial diagnostic and parentage genotyping applications as automated genotyping systems have been developed that yield accurate genotypes. Unfortunately, a large number of highly informative public SNP markers tested in ...

To enhance capabilities for genetic analyses in rainbow trout, a large suite of polymorphic markers that are amenable to high-throughput genotyping protocols must be developed. However, the evolutionarily recent whole genome duplication event complicates the use of standard approaches in the discove...

The calpains and calpastatin (CAST) make up a major cytosolic proteolytic system, the calpain-calpastatin system, found in mammalian tissues. The relative levels of the components of the calpain-calpastatin system determine the extent of meat tenderization during postmortem storage. Calpastatin (CAST) is a protein inhibitor of the ubiquitous calcium-dependent proteases-micro-calpain and m-calpain. Polymorphisms in the bovine, ovine and pig CAST gene have been associated with meat tenderness but little is known about how caprine CAST gene may affect goat meat quality traits. In this study we selected different parts of the CAST gene: 1) that have been previously reported to be polymorphic, intron 5 and 12 and 3'UTR; 2) first time explored (exon 3, 7 and 8 and part of intron 7 and 8) to investigate polymorphic status of caprine CAST gene. Using comparative sequencing ten novel SN Ps located in exon 3 and intron 5, 7 and 8 were identified. Previously reported SNPs in intron 5, 3'UTR and intron 12 were absent. Sequence analysis revealed a non synonymous amino acid variation in exon 3, which would result in Lys/Arg substitution in the corresponding protein sequence. Considerable variation was detected in intronic regions. Twenty-four InDel were also recognized in intronic regions (15) and 3'UTR (9). All the sequences shared high homology with published bovine and ovine sequences. Three PCR-RFLP loci have been established for further analyzing genetic polymorphism in indigenous goats. PMID:23866627

Autism is widely believed to be a heterogeneous disorder; diagnosis is currently based solely on clinical criteria, although genetic, as well as environmental, influences are thought to be prominent factors in the etiology of most forms of autism. Our goal is to determine whether a predictive model based on single-nucleotidepolymorphisms (SNPs)…

The dramatic decrease in the cost of sequencing a human genome is leading to an era in which a wide range of students will benefit from having an understanding of human genetic variation. Since over 90% of sequence variation between humans is in the form of single nucleotidepolymorphisms (SNPs), a laboratory exercise has been devised in order to…

We identified approximately 13000 putative single nucleotidepolymorphisms (SNPs) by comparison of repeat-masked BAC-end sequences from the cattle RPCI-42 BAC library with whole-genome shotgun contigs of cattle genome assembly Btau 1.0. Genotyping of a subset of these SNPs was performed on a panel ...

Domesticated Asian rice (Oryza sativa) is one of the oldest domesticated crop species in the world, having fed more people than any other plant in human history. We report the patterns of DNA sequence variation in rice and its wild ancestor, O. rufipogon, across 111 randomly chosen gene fragments, and use these to infer the evolutionary dynamics that led to the origins of rice. There is a genome-wide excess of high-frequency derived single nucleotidepolymorphisms (SNPs) in O. sativa varieties, a pattern that has not been reported for other crop species. We developed several alternative models to explain contemporary patterns of polymorphisms in rice, including a (i) selectively neutral population bottleneck model, (ii) bottleneck plus migration model, (iii) multiple selective sweeps model, and (iv) bottleneck plus selective sweeps model. We find that a simple bottleneck model, which has been the dominant demographic model for domesticated species, cannot explain the derived nucleotidepolymorphism site frequency spectrum in rice. Instead, a bottleneck model that incorporates selective sweeps, or a more complex demographic model that includes subdivision and gene flow, are more plausible explanations for patterns of variation in domesticated rice varieties. If selective sweeps are indeed the explanation for the observed nucleotide data of domesticated rice, it suggests that strong selection can leave its imprint on genome-wide polymorphism patterns, contrary to expectations that selection results only in a local signature of variation. PMID:17907810

In contrast to high genetic diversity of mitochondrial DNA (mtDNA), equine Y chromosome shows extremely low variability, implying limited patrilines in the domesticated horse. In this study, we applied direct sequencing and restriction fragment length polymorphism (RFLP) methods to investigate the polymorphisms of 33 Y chromosome specific loci in 304 Chinese indigenous horses from 13 breeds. Consequently, two Y-single nucleotidepolymorphisms (SNPs) (Y-45701/997 and Y-50869) and one Y-indel (Y-45288) were identified. Of those, the Y-50869 (T>A) revealed the highest variation frequency (24.67%), whereas it was only 3.29% and 1.97% in Y-45288 (T/-) and Y-45701/997 (G>T) locus, respectively. These three mutations accounted for 27.96% of the total samples and identified five Y-SNP haplotypes, demonstrating genetic diversity of Y chromosome in Chinese horses. In addition, all the five Y-SNP haplotypes were shared by different breeds. Among 13 horse breeds analyzed, Balikun horse displayed the highest nucleotide diversity (π = 5.6×10−4) and haplotype diversity (h = 0.527), while Ningqiang horse showed the lowest nucleotide diversity (π = 0.00000) and haplotype diversity (h = 0.000). The results also revealed that Chinese horses had a different polymorphic pattern of Y chromosome from European and American horses. In conclusion, Chinese horses revealed genetic diversity of Y chromosome, however more efforts should be made to better understand the domestication and paternal origin of Chinese indigenous horses. PMID:26104513

Fluorescence quenching by dye dimer formation has been utilized to develop hairpin-structured DNA probes for the detection of a single nucleotidepolymorphism (SNP) in the penicillin target gene pbp2x, which is implicated in the penicillin resistance of Streptococcus pneumoniae. We designed two specific DNA probes for the identification of the pbp2x genes from a penicillin susceptible strain R6 and a resistant strain Streptococcus mitis 661 using green-fluorescent tetramethylrhodamine (TMR) and red-fluorescent DY-636, respectively. Hybridization of each of the probes to its respective target DNA sequence opened the DNA hairpin probes, consequently breaking the nonfluorescent dye dimers into fluorescent species. This hybridization of the target with the hairpin probe achieved single nucleotide specific detection at nanomolar concentrations via increased fluorescence.

Pyrosequencing, a non-electrophoretic method for DNA sequencing, is emerging as a popular platform for analysis of single nucleotidepolymorphisms (SNPs). This technology has the advantage of accuracy, ease-of-use, and high flexibility for different applications. Here, we review the methodology and the use of this technique for SNP genotyping, SNP discovery, haplotyping, and allelic frequency studies. In addition, we describe new schemes for template preparation and multiplexing as an effort for cost reduction in large-scale studies. PMID:11968080

Background Leprosy was common in Europe eight to twelve centuries ago but molecular confirmation of this has been lacking. We have extracted M. leprae ancient DNA (aDNA) from medieval bones and single nucleotidepolymorphism (SNP) typed the DNA, this provides insight into the pattern of leprosy transmission in Europe and may assist in the understanding of M. leprae evolution. Methods and Findings Skeletons have been exhumed from 3 European countries (the United Kingdom, Denmark and Croatia) and are dated around the medieval period (476 to 1350 A.D.). we tested for the presence of 3 previously identified single nucleotidepolymorphisms (SNPs) in 10 aDNA extractions. M. leprae aDNA was extracted from 6 of the 10 bone samples. SNP analysis of these 6 extractions were compared to previously analysed European SNP data using the same PCR assays and were found to be the same. Testing for the presence of SNPs in M. leprae DNA extracted from ancient bone samples is a novel approach to analysing European M. leprae DNA and the findings concur with the previously published data that European M. leprae strains fall in to one group (SNP group 3). Conclusions These findings support the suggestion that the M. leprae genome is extremely stable and show that archaeological M. leprae DNA can be analysed to gain detailed information about the genotypic make-up of European leprosy, which may assist in the understanding of leprosy transmission worldwide. PMID:19847306

Candidate genetic associations with acute GVHD (aGVHD) were evaluated with the use of genotyped and imputed single-nucleotidepolymorphism data from genome-wide scans of 1298 allogeneic hematopoietic cell transplantation (HCT) donors and recipients. Of 40 previously reported candidate SNPs, 6 were successfully genotyped, and 10 were imputed and passed criteria for analysis. Patient and donor genotypes were assessed for association with grades IIb-IV and III-IV aGVHD, stratified by donor type, in univariate and multivariate allelic, recessive and dominant models. Use of imputed genotypes to replicate previous IL10 associations was validated. Similar to previous publications, the IL6 donor genotype for rs1800795 was associated with a 20%-50% increased risk for grade IIb-IV aGVHD after unrelated HCT in the allelic (adjusted P = .011) and recessive (adjusted P = .0013) models. The donor genotype was associated with a 60% increase in risk for grade III-IV aGVHD after related HCT (adjusted P = .028). Other associations were found for IL2, CTLA4, HPSE, and MTHFR but were inconsistent with original publications. These results illustrate the advantages of using imputed single-nucleotidepolymorphism data in genetic analyses and demonstrate the importance of validation in genetic association studies. PMID:22282500

Single nucleotidepolymorphism(SNP) is the most common type of sequence difference between alleles, which can be used as a kind of high-throughput genetic marker. Several different routes have been developed to discover and identify SNP. These include the direct sequencing of PCR amplicons, electronic SNP(eSNP) and so on. SNP assays have been made in many crop species such as maize and soybean. The elite germplasm of some crops have been narrowed in genetic diversity, increasing the amount of linkage disequilibrium (LD) present and facilitating the association of SNP haplotypes at candidate gene loci with phenotypes. SNP analysis has been broadly used in the field of plant gene mapping, integration of genetic and physical maps, DNA marker-assisted breeding and functional genomics. PMID:15639972

The ability to discriminate nucleic acid sequences is necessary for a wide variety of applications: high throughput screening, distinguishing genetically modified organisms (GMOs), molecular computing, differentiating biological markers, fingerprinting a specific sensor response for complex systems, etc. Hybridization-based target recognition and discrimination is central to the operation of nucleic acid sensor systems. Therefore developing a quantitative correlation between mishybridization events and sensor out put is critical to the accurate interpretation of results. In this work, using experimental data produced by introducing single mutations (single nucleotidepolymorphisms, SNPs) in the probe sequence of computational catalytic molecular beacons (deoxyribozyme gates) [1], we investigate coding theory algorithms for uniquely categorizing SNPs based on the calculation of syndromes. PMID:17947098

Single NucleotidePolymorphisms (SNPs) are the most frequent form of DNA variation in the genome. SNPs are genetic markers which are bi-allelic in nature and grow at a very fast rate. Current genomic databases contain information on several million SNPs. More than 6 million SNPs have been identified and the information is publicly available through the efforts of the SNP Consortium and others data bases. The NCBI plays a major role in facillating the identification and cataloging of SNPs through creation and maintenance of the public SNP database (dbSNP) by the biomedical community worldwide and stimulate many areas of biological research including the identification of the genetic components of disease. In this review article, we are compiling the existing SNP databases, research status and their application. PMID:21717869

As more and more genomic DNAs are sequenced to characterize human genetic variations, the demand for a very fast and accurate method to genomically position these DNA sequences is high. We have developed a new mapping method that does not require sequence alignment. In this method, we first identified DNA fragments of 15 bp in length that are unique in the human genome and then used them to position single nucleotidepolymorphism (SNP) sequences. By use of four desktop personal computers with AMD K7 (1 GHz) processors, our new method mapped more than 1.6 million SNP sequences in 20 hr and achieved a very good agreement with mapping results from alignment-based methods. PMID:12097348

Single nucleotidepolymorphisms (SNPs) have been classically used for dissecting various human complex disorders using candidate gene studies. During the last decade, large scale SNP analysis, i.e. genome-wide association studies (GWAS) have provided an agnostic approach to identify possible genetic loci associated with heterogeneous disease such as cancer susceptibility, prognosis of survival or drug response. Further, the advent of new technologies, including microarray-based genotyping as well as high throughput next generation sequencing has opened new avenues for SNPs to be used in clinical practice. It is speculated that the utility of SNPs to understand the mechanisms, biology of variable drug response and ultimately treatment individualization based on the individual's genome composition will be indispensable in the near future. In the current review, we discuss the advantages and disadvantages of the clinical utility of genetic variants in disease risk-prediction, prognosis, clinical outcome and pharmacogenomics. The lessons and challenges for the utility of SNP-based biomarkers are also discussed, including the need for additional functional validation studies. PMID:26398894

Kit gene is a genetic determinant of horse white coat color which has been a highly valued trait in horses for at least 2,000 years. Single nucleotidepolymorphisms (SNPs) in Kit are of importance due to their strong associations with melanoblast survival during embryonic development. In this study, a mutation analysis of all 21 Kit exons in 14 Chinese domestic horse breeds revealed six SNPs (g.91214T>G, g.143245T>G, g.164297C>T, g.170189C>T, g.171356C>G, and g.171471G>A), which located in 5'-UTR region, intron 6, exon 15, exon 20, intron 20, and exon 21 of the equine Kit gene, respectively. Subsequently, these six SNPs loci were genotyped in 632 Chinese horses by PCR-RFLP or direct sequencing. The six SNPs together defined 18 haplotypes, demonstrating abundant haplotype diversities in Chinese horses. All the mutant alleles and haplotypes were shared among different breeds. But fewer mutations were detected in horses from China than that from abroad, indicating that Chinese horses belong to a more ancient genetic pool. This study will provide fundamental genetic information for evaluating the genetic diversity of Kit gene in Chinese indigenous horse breeds. PMID:27348891

Quantifying dispersal within wild populations is an important but challenging task. Here we present a method to estimate contemporary, individual-based dispersal distance from noninvasively collected samples using a specialized panel of 96 SNPs (single nucleotidepolymorphisms). One main issue in conducting dispersal studies is the requirement for a high sampling resolution at a geographic scale appropriate for capturing the majority of dispersal events. In this study, fecal samples of brown bear (Ursus arctos) were collected by volunteer citizens, resulting in a high sampling resolution spanning over 45,000 km(2) in Gävleborg and Dalarna counties in Sweden. SNP genotypes were obtained for unique individuals sampled (n = 433) and subsequently used to reconstruct pedigrees. A Mantel test for isolation by distance suggests that the sampling scale was appropriate for females but not for males, which are known to disperse long distances. Euclidean distance was estimated between mother and offspring pairs identified through the reconstructed pedigrees. The mean dispersal distance was 12.9 km (SE 3.2) and 33.8 km (SE 6.8) for females and males, respectively. These results were significantly different (Wilcoxon's rank-sum test: P-value = 0.02) and are in agreement with the previously identified pattern of male-biased dispersal. Our results illustrate the potential of using a combination of noninvasively collected samples at high resolution and specialized SNPs for pedigree-based dispersal models. PMID:26357536

Autism is widely believed to be a heterogeneous disorder; diagnosis is currently based solely on clinical criteria, although genetic, as well as environmental, influences are thought to be prominent factors in the etiology of most forms of autism. Our goal is to determine whether a predictive model based on single-nucleotidepolymorphisms (SNPs) can predict symptom severity of autism spectrum disorder (ASD). We divided 118 ASD children into a mild/moderate autism group (n = 65) and a severe autism group (n = 53), based on the Childhood Autism Rating Scale (CARS). For each child, we obtained 29 SNPs of 9 ASD-related genes. To generate predictive models, we employed three machine-learning techniques: decision stumps (DSs), alternating decision trees (ADTrees), and FlexTrees. DS and FlexTree generated modestly better classifiers, with accuracy = 67%, sensitivity = 0.88 and specificity = 0.42. The SNP rs878960 in GABRB3 was selected by all models, and was related associated with CARS assessment. Our results suggest that SNPs have the potential to offer accurate classification of ASD symptom severity. PMID:21786105

Quantifying dispersal within wild populations is an important but challenging task. Here we present a method to estimate contemporary, individual-based dispersal distance from noninvasively collected samples using a specialized panel of 96 SNPs (single nucleotidepolymorphisms). One main issue in conducting dispersal studies is the requirement for a high sampling resolution at a geographic scale appropriate for capturing the majority of dispersal events. In this study, fecal samples of brown bear (Ursus arctos) were collected by volunteer citizens, resulting in a high sampling resolution spanning over 45,000 km2 in Gävleborg and Dalarna counties in Sweden. SNP genotypes were obtained for unique individuals sampled (n = 433) and subsequently used to reconstruct pedigrees. A Mantel test for isolation by distance suggests that the sampling scale was appropriate for females but not for males, which are known to disperse long distances. Euclidean distance was estimated between mother and offspring pairs identified through the reconstructed pedigrees. The mean dispersal distance was 12.9 km (SE 3.2) and 33.8 km (SE 6.8) for females and males, respectively. These results were significantly different (Wilcoxon’s rank-sum test: P-value = 0.02) and are in agreement with the previously identified pattern of male-biased dispersal. Our results illustrate the potential of using a combination of noninvasively collected samples at high resolution and specialized SNPs for pedigree-based dispersal models. PMID:26357536

Genotyping of single nucleotidepolymorphisms (SNPs) allows diagnosis of human genetic disorders associated with single base mutations. Conventional SNP genotyping methods are capable of providing either accurate or high-throughput detection, but are still labor-, time-, and resource-intensive. Microfluidics has been applied to SNP detection to provide fast, low-cost, and automated alternatives, although these applications are still limited by either accuracy or throughput issues. To address this challenge, we present a MEMS-based SNP genotyping approach that uses solid-phase-based reactions in a single microchamber on a temperature control chip. Polymerase chain reaction (PCR), allele specific single base extension (SBE), and desalting on microbeads are performed in the microchamber, which is coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to analyze the SBE product. Experimental results from genotyping of the SNP on exon 1 of the HBB gene, which causes sickle cell anemia, demonstrate the potential of the device for rapid, accurate, multiplexed and high-throughput detection of SNPs. PMID:24729659

Single-nucleotidepolymorphisms (SNPs) are the most abundant type of genetic variations; they provide the genetic fingerprint of individuals and are essential for genetic biomarker discoveries. Accurate detection of SNPs is of great significance for disease prevention, diagnosis and prognosis, and for prediction of drug response and clinical outcomes in patients. Nevertheless, conventional SNP genotyping methods are still limited by insufficient accuracy or labor-, time-, and resource-intensive procedures. Microfluidics has been increasingly utilized to improve efficiency; however, the currently available microfluidic genotyping systems still have shortcomings in accuracy, sensitivity, throughput and multiplexing capability. To address these challenges, we developed a multi-step SNP genotyping microfluidic device, which performs single-base extension of SNP specific primers and solid-phase purification of the extension products on a temperature-controlled chip. The products are ready for immediate detection by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), providing identification of the alleles at the target loci. The integrated device enables efficient and automated operation, while maintaining the high accuracy and sensitivity provided by MS. The multiplex genotyping capability was validated by performing rapid, accurate and simultaneous detection of 4 loci on a synthetic template. The microfluidic device has the potential to perform automatic, accurate, quantitative and high-throughput assays covering a broad spectrum of applications in biological and clinical research, drug development and forensics. PMID:26594354

Single NucleotidePolymorphisms (SNPs) found in Genome-Wide Association Study (GWAS) mainly influence the susceptibility of complex diseases, but they still could not comprehensively explain the relationships between mutations and diseases. Interactions between SNPs are considered so important for deeply understanding of those relationships that several strategies have been proposed to explore such interactions. However, part of those methods perform poorly when marginal effects of disease loci are weak or absent, others may lack of considering high-order SNPs interactions, few methods have achieved the requirements in both performance and accuracy. Considering the above reasons, not only low-order, but also high-order SNP interactions as well as main-effect SNPs, should be taken into account in detection methods under an acceptable computational complexity. In this paper, a new pairwise (or low-order) interaction detection method IG (Interaction Gain) is introduced, in which disease models are not required and parallel computing is utilized. Furthermore, high-order SNP interactions were proposed to be detected by finding closely connected function modules of the network constructed from IG detection results. Tested by a wide range of simulated datasets and four WTCCC real datasets, the proposed methods accurately detected both low-order and high-order SNP interactions as well as disease-associated main-effect SNPS and it surpasses all competitors in performances. The research will advance complex diseases research by providing more reliable SNP interactions. PMID:25763929

Single NucleotidePolymorphisms (SNPs) found in Genome-Wide Association Study (GWAS) mainly influence the susceptibility of complex diseases, but they still could not comprehensively explain the relationships between mutations and diseases. Interactions between SNPs are considered so important for deeply understanding of those relationships that several strategies have been proposed to explore such interactions. However, part of those methods perform poorly when marginal effects of disease loci are weak or absent, others may lack of considering high-order SNPs interactions, few methods have achieved the requirements in both performance and accuracy. Considering the above reasons, not only low-order, but also high-order SNP interactions as well as main-effect SNPs, should be taken into account in detection methods under an acceptable computational complexity. In this paper, a new pairwise (or low-order) interaction detection method IG (Interaction Gain) is introduced, in which disease models are not required and parallel computing is utilized. Furthermore, high-order SNP interactions were proposed to be detected by finding closely connected function modules of the network constructed from IG detection results. Tested by a wide range of simulated datasets and four WTCCC real datasets, the proposed methods accurately detected both low-order and high-order SNP interactions as well as disease-associated main-effect SNPS and it surpasses all competitors in performances. The research will advance complex diseases research by providing more reliable SNP interactions. PMID:25763929

Systemic Autoimmune Diseases, a group of chronic inflammatory conditions, have variable symptoms and difficult diagnosis. In order to reclassify them based on genetic markers rather than clinical criteria, we performed clustering of Single NucleotidePolymorphisms. However naive approaches tend to group patients primarily by their geographic origin. To reduce this “ancestry signal”, we developed SNPClust, a method to select large sources of ancestry-independent genetic variations from all variations detected by Principal Component Analysis. Applied to a Systemic Lupus Erythematosus case control dataset, SNPClust successfully reduced the ancestry signal. Results were compared with association studies between the cases and controls without or with reference population stratification correction methods. SNPClust amplified the disease discriminating signal and the ratio of significant associations outside the HLA locus was greater compared to population stratification correction methods. SNPClust will enable the use of ancestry-independent genetic information in the reclassification of Systemic Autoimmune Diseases. SNPClust is available as an R package and demonstrated on the public Human Genome Diversity Project dataset at https://github.com/ThomasChln/snpclust. PMID:27490238

The genotyping of single nucleotidepolymorphisms (SNPs) has successfully contributed to the study of complex diseases more than any other technology to date. Genome-wide association studies (GWAS) using 10,000s to >1,000,000 SNPs have identified 1000s of statistically significant SNPs pertaining to 17 different human disease and trait categories. Post-GWAS fine-mapping studies using 10,000s to 100,000s SNPs on a microarray have narrowed the region of interest for many of these GWAS findings; in addition, independent signals within the original GWAS region have been identified. Focused content, SNP-based microarrays such as the human exome, for example, have too been used successfully to identify novel disease associations. Success has come to studies where 100s to 10,000s (mostly) to >100,000 samples were genotyped. For the time being, SNP-based microarrays remain cost-effective especially when studying large numbers of samples compared to other "genotyping" technologies including next generation sequencing. In this unit, protocols for manual (LIMS-free), semi-manual, and automated processing of BeadChip microarrays are presented. Lower throughput studies will find value in the manual and semi-manual protocols, while all types of studies--low-, medium-, and high-throughput--will find value in the semi-manual and automated protocols. PMID:23853082

For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that have recently revolutionized human, mouse and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila using an STS-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that the genome. The majority of these markers are single nucleotidepolymorphisms (SNPs) and sequences for these variants are provided in an accessible format. The average density of the new markers is 1 marker per 225 kb on the autosomes and 1 marker per 1 Mb on the X chromosome. We include in this survey a set of P-element strains that provide additional utility for high-resolution mapping. We demonstrate one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community.

Systemic Autoimmune Diseases, a group of chronic inflammatory conditions, have variable symptoms and difficult diagnosis. In order to reclassify them based on genetic markers rather than clinical criteria, we performed clustering of Single NucleotidePolymorphisms. However naive approaches tend to group patients primarily by their geographic origin. To reduce this "ancestry signal", we developed SNPClust, a method to select large sources of ancestry-independent genetic variations from all variations detected by Principal Component Analysis. Applied to a Systemic Lupus Erythematosus case control dataset, SNPClust successfully reduced the ancestry signal. Results were compared with association studies between the cases and controls without or with reference population stratification correction methods. SNPClust amplified the disease discriminating signal and the ratio of significant associations outside the HLA locus was greater compared to population stratification correction methods. SNPClust will enable the use of ancestry-independent genetic information in the reclassification of Systemic Autoimmune Diseases. SNPClust is available as an R package and demonstrated on the public Human Genome Diversity Project dataset at https://github.com/ThomasChln/snpclust. PMID:27490238

Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disorder that displays various clinical features and results in cerebral infarct or hemorrhagic stroke. Specific genes associated with the disease have not yet been identified, making identification of at-risk patients difficult before clinical manifestation. Familial MMD is not uncommon, with as many as 15% of MMD patients having a family history of the disease, suggesting a genetic etiology. Studies of single nucleotidepolymorphisms (SNPs) in MMD have mostly focused on mechanical stress on vessels, endothelium, and the relationship to atherosclerosis. In this review, we discuss SNPs studies targeting the genetic etiology of MMD. Genetic analyses in familial MMD and genome-wide association studies represent promising strategies for elucidating the pathophysiology of this condition. This review also discusses future research directions, not only to offer new insights into the origin of MMD, but also to enhance our understanding of the genetic aspects of MMD. There have been several SNP studies of MMD. Current SNP studies suggest a genetic contribution to MMD, but further reliable and replicable data are needed. A large cohort or family-based design would be important. Modern SNP studies of MMD depend on novel genetic, experimental, and database methods that will hopefully hasten the arrival of a consensus conclusion. PMID:26180609

Single NucleotidePolymorphisms (SNPs) are highly abundant, widespread and evenly distributed markers, which can be easily genotyped using high-throughput assays. These characteristics explain their increasing popularity in genome analyses such as quantitative trait loci mapping, linkage disequilibr...

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal emergency. The purpose of this study is to determine if functional single nucleotidepolymorphisms (SNPs) in immune-modulating genes pre-dispose infants to NEC. After Institutional Review Board approval and parental consent, buccal swabs were collected for DNA extraction. TaqMan allelic discrimination assays and BglII endonuclease digestion were used to genotype specific inflammatory cytokines and TRIM21. Statistical analysis was completed using logistic regression. 184 neonates were analyzed in the study. Caucasian neonates with IL-6 (rs1800795) were over 6 times more likely to have NEC (p = 0.013; OR = 6.61, 95% CI 1.48–29.39), and over 7 times more likely to have Stage III disease (p = 0.011; OR = 7.13, (95% CI 1.56–32.52). Neonates with TGFβ-1 (rs2241712) had a decreased incidence of NEC-related perforation (p = 0.044; OR = 0.28, 95% CI: 0.08–0.97) and an increased incidence of mortality (p = 0.049; OR = 2.99, 95% CI: 1.01 – 8.86). TRIM21 (rs660) was associated with NEC-related intestinal perforation (p = 0.038; OR = 4.65, 95% CI 1.09–19.78). In premature Caucasian neonates, the functional SNP IL-6 (rs1800795) is associated with both the development and increased severity of NEC. TRIM21 (rs660) and TGFβ-1 (rs2241712) were associated with NEC- related perforation in all neonates in the cohort. These findings suggest a possible genetic role in the development of NEC. PMID:26670709

Single nucleotidepolymorphisms (SNPs) are nucleotide substitution mutations that tend to be at high densities within eukaryotic genomes. The development of assays that detect allelic variation at SNP loci is attractive for genome mapping, population genetics, and phylogeographic applications. A p...

BACKGROUND: To enhance capabilities for genomic analyses in rainbow trout, such as genomic selection, a large suite of polymorphic markers that are amenable to high-throughput genotyping protocols must be identified. Expressed Sequence Tags (ESTs) have been used for single nucleotidepolymorphism (...

Single-nucleotidePolymorphism (SNP) markers are by far the most common form of DNA polymorphism in a genome. The objectives of this study were to discover SNPs in common bean comparing sequences from coding and non-coding regions obtained from Genbank and genomic DNA and to compare sequencing resu...

Thirty-two individuals representing coastal and inland populations of steelhead and rainbow trout (Oncorhynchus mykiss) were sequenced at 15 ESTs and 9 microsatellite loci to identify single nucleotidepolymorphisms (SNPs). Sixty-two polymorphisms were discovered during the screen and 13 were devel...

Musa (banana and plantain) is an important genus for the global export market and in local markets where it provides staple food for approximately 400 million people. Hybridization and polyploidization of several (sub)species, combined with vegetative propagation and human selection have produced a complex genetic history. We describe the application of the Ecotilling method for the discovery and characterization of nucleotidepolymorphisms in diploid and polyploid accessions of Musa. We discovered over 800 novel alleles in 80 accessions. Sequencing and band evaluation shows Ecotilling to be a robust and accurate platform for the discovery of polymorphisms in homologous and homeologous gene targets. In the process of validating the method, we identified two single nucleotidepolymorphisms that may be deleterious for the function of a gene putatively important for phototropism. Evaluation of heterozygous polymorphism and haplotype blocks revealed a high level of nucleotide diversity in Musa accessions. We further applied a strategy for the simultaneous discovery of heterozygous and homozygous polymorphisms in diploid accessions to rapidly evaluate nucleotide diversity in accessions of the same genome type. This strategy can be used to develop hypotheses for inheritance patterns of nucleotidepolymorphisms within and between genome types. We conclude that Ecotilling is suitable for diversity studies in Musa, that it can be considered for functional genomics studies and as tool in selecting germplasm for traditional and mutation breeding approaches. PMID:20589365

Genome-wide association studies have identified and repeatedly confirmed the association of rs3197999 in MST1 with inflammatory bowel disease (IBD). However, the underlying pathophysiology remains unclear. rs3197999 is a non-synonymous single-nucleotidepolymorphism which modifies the function of macrophage stimulating protein-1 (MST1). We show by haplotyping that rs3197999 is in linkage disequilibrium with rs1050450 in GPX1, with almost complete cosegregation of the minor alleles. As shown by immunoassay, rs3197999 influences the MST-1 level in serum. But also rs1050450 causes an amino acid exchange in glutathione peroxidase 1 (GPx-1) and reduced activity of this antioxidant enzyme. The association of GPx deficiency and IBD in mice was already shown. We propose that GPx-1 is a better candidate than MST1 for the pathophysiologic link between IBD locus 12 and IBD. PMID:26355565

Comparative genomics, analyzing variation among individual genomes, is an area of intense investigation. DNA sequencing is usually employed to look for polymorphisms and mutations. Pyrosequencing, a real-time DNA sequencing method, is emerging as a popular platform for comparative genomics. Here we review the use of this technology for mutation scanning, polymorphism discovery and chemical haplotyping. We describe the methodology and accuracy of this technique and discuss how to reduce the cost for large-scale analysis. PMID:18628881

A new MALDI-TOF based detection assay was developed for analysis of single nucleotidepolymorphisms (SNPs). It is a significant modification on the classic three-step minisequencing method, which includes a polymerase chain reaction (PCR), removal of excess nucleotides and primers, followed by primer extension in the presence of dideoxynucleotides using modified thermostable DNA polymerase. The key feature of this novel assay is reliance upon deoxynucleotide mixes, lacking one of the nucleotides at the polymorphic position. During primer extension in the presence of depleted nucleotide mixes, standard thermostable DNA polymerases dissociate from the template at positions requiring a depleted nucleotide; this principal was harnessed to create a genotyping assay. The assay design requires a primer- extension primer having its 3'-end one nucleotide upstream from the interrogated site. The assay further utilizes the same DNA polymerase in both PCR and the primer extension step. This not only simplifies the assay but also greatly reduces the cost per genotype compared to minisequencing methodology. We demonstrate accurate genotyping using this methodology for two SNPs run in both singleplex and duplex reactions. We term this assay nucleotide depletion genotyping (NUDGE). Nucleotide depletion genotyping could be extended to other genotyping assays based on primer extension such as detection by gel or capillary electrophoresis. PMID:14654708

Bulk segregant analysis using microarrays, and extreme array mapping have recently been used to rapidly identify genomic regions associated with phenotypes in multiple species. These experiments, however require the identification of single feature polymorphisms between the cross parents for each ne...

Aim: An attempt has been made to study the Myxovirus resistant (Mx1) gene polymorphism in Japanese quail. Materials and Methods: In the present, investigation four fragments viz. Fragment I of 185 bp (Exon 3 region), Fragment II of 148 bp (Exon 5 region), Fragment III of 161 bp (Exon 7 region), and Fragment IV of 176 bp (Exon 13 region) of Mx1 gene were amplified and screened for polymorphism by polymerase chain reaction-single-strand conformation polymorphism technique in 170 Japanese quail birds. Results: Out of the four fragments, one fragment (Fragment II) was found to be polymorphic. Remaining three fragments (Fragment I, III, and IV) were found to be monomorphic which was confirmed by custom sequencing. Overall nucleotide sequence analysis of Mx1 gene of Japanese quail showed 100% homology with common quail and more than 80% homology with reported sequence of chicken breeds. Conclusion: The Mx1 gene is mostly conserved in Japanese quail. There is an urgent need of comprehensive analysis of other regions of Mx1 gene along with its possible association with the traits of economic importance in Japanese quail. PMID:27047057

Genome-wide association studies (GWAS) may benefit from using haplotype information for making marker-phenotype associations. Several rationales for grouping single nucleotidepolymorphisms (SNPs) into haplotype blocks exist, but any advantage may depend on the genetic architecture of traits, patter...

GeneSeek designed a new version of the GeneSeek Genomic Profiler HD BeadChip for Dairy Cattle, which had >77,000 single nucleotidepolymorphisms (SNPs). A set of >140,000 SNPs was selected that included all SNPs on the existing GeneSeek chip, all SNPs used in U.S. national genomic evaluations, SNPs ...

The association of a single nucleotidepolymorphism (SNP) of calpain 1 (CAPN1) gene with shear force of 2.54 cm steaks from M. longissimus dorsi from Gannan yaks (Bos grunniens, n = 181) was studied. The experimental design was a repeated measures with the main unit in a completely randomized design...

High-throughput single nucleotidepolymorphism (SNP) genotyping has become the dominant approach to genomic analysis and genetic manipulation in many crop plants. In cotton (Gossypium spp), however, only a very limited number of loci and a dearth of information have been generated from SNP genotypi...

Escherichia coli O157:H7 is a zoonotic human pathogen for which cattle are an important reservoir host. Using both previously published and new sequencing data, a 48-locus single nucleotidepolymorphism (SNP) based typing panel was developed that redundantly identified eleven genogroups that span ...

Call rate has been used as a measure of quality on both a single nucleotidepolymorphism (SNP) and animal basis since SNP genotypes were first used in genomic evaluation of dairy cattle. The genotyping laboratories perform initial quality control screening and genotypes that fail are usually exclude...

Accuracy of genomic evaluation is expected to increase when more markers are used because of better tracking of causative genetic variants. However, Illumina BovineHD genotypes based on 777,962 single nucleotidepolymorphisms (SNP) have not been used for US genomic evaluation because the small relia...

Methods to rapidly identify serotypes of Salmonella enterica subspecies I are of vital importance for protecting the safety of food. To supplement the serotyping method dkgB-linked intergenic sequence ribotyping (ISR), single nucleotidepolymorphisms (SNPs) were characterized within adenylate cyclas...

Our previous genetic studies demonstrated that resistance to avian coccidiosis was linked with microsatellite markers LEI0071 and LEI0101 on chromosome 1. In this study, the associations between parameters of resistance to coccidiosis and single nucleotidepolymorphisms (SNPs) in 3 candidate genes ...

The association of single nucleotidepolymorphisms (SNPs) of calpastatin (CAST) gene with shear force of 2.54 cm steaks from M. longissimus dorsi from Gannan yaks (Bos grunniens, n=181) was studied. Yaks were harvested at 2, 3, and 4 yr of age (n=51, 59, and 71, respectively), and samples of each ya...

Single nucleotidepolymorphisms (SNPs) can be used to generate DNA-based fingerprints for individual identification. The efficiency of DNA fingerprinting is greatest when the frequency of both SNP alleles is near 0.50. A number of SNPs have been identified in cattle populations with minor allele f...

Fusarium head blight (FHB) is a destructive disease that reduces wheat grain yield and quality. To date, the quantitative trait locus on 3BS (Fhb1) from Sumai 3 has shown the largest effect on FHB resistance. Single nucleotidepolymorphism (SNP) is the most common form of genetic variation and suita...

The development of single nucleotidepolymorphism (SNP) markers in maize offer the opportunity to utilize DNA markers in many new areas of population genetics, gene discovery, plant breeding, and germplasm identification. However, the steps from sequencing and SNP discovery to SNP marker design and ...

The objective was to assess the association of single nucleotidepolymorphisms (SNP) developed on the CAST gene, with longissimus tenderness. Forty one SNP were identified in the CAST gene and assays were developed. Markers were scattered throughout the gene. These markers, in conjunction with a com...

Genome scans in the pig have identified a region on chromosome 2 (SSC2) associated with tenderness. Calpastatin is a likely positional candidate gene in this region because of its inhibitory role in the calpain system that is involved in postmortem tenderization. Novel single nucleotidepolymorphism...

Discovery of single nucleotidepolymorphisms (SNPs) may lead to development of marker panels predictive of tolerance to high dietary nitrate (NO3-). The aims of this research were to identify SNPs in Arginiosuccinate Lyase (ASL), determine the relationship of ASL SNP genotypes on NO3- tolerance, an...

The objective was to assess the association of single nucleotidepolymorphisms (SNP) developed on candidate genes residing under previously identified quantitative trait loci for marbling score and meat tenderness. Two hundred five SNP were identified on twenty candidate genes. Genes selected under ...

Recombination is a main factor determining nucleotide variability in different regions of the genome. Chromosomal inversions, which are ubiquitous in the genus Drosophila, are known to reduce and redistribute recombination, and thus their specific effect on nucleotide variation may be of major importance as an explanatory factor for levels of DNA variation. Here, we use the coalescent approach to study this effect. First, we develop analytical expressions to predict nucleotide variability in old inversion polymorphisms that have reached mutation-drift-flux equilibrium. The effects on nucleotide variability of a new arrangement appearing in the population and reaching a stable polymorphism are then studied by computer simulation. We show that inversions modulate nucleotide variability in a complex way. The establishment of an inversion polymorphism involves a partial selective sweep that eliminates part of the variability in the population. This is followed by a slow convergence to the equilibrium values. During this convergence, regions close to the breakpoints exhibit much lower variability than central regions. However, at equilibrium, regions close to the breakpoints have higher levels of variability and differentiation between arrangements than regions in the middle of the inverted segment. The implications of these findings for overall variability levels during the evolution of Drosophila species are discussed. PMID:10835391

Background Preeclampsia is one of the leading causes of maternal and neonatal morbidity and mortality in the world, but its appearance is still unpredictable and its pathophysiology has not been entirely elucidated. Genetic studies have associated single nucleotidepolymorphisms in genes encoding nitric oxide synthase and matrix metalloproteases with preeclampsia, but the results are largely inconclusive across different populations. Objectives To investigate the association of single nucleotidepolymorphisms (SNPs) in NOS3 (G894T, T-786C, and a variable number of tandem repetitions VNTR in intron 4), MMP2 (C-1306T), and MMP9 (C-1562T) genes with preeclampsia in patients from Southeastern Brazil. Methods This prospective case-control study enrolled 77 women with preeclampsia and 266 control pregnant women. Clinical data were collected to assess risk factors and the presence of severe complications, such as eclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome. Results We found a significant association between the single nucleotidepolymorphism NOS3 T-786C and preeclampsia, independently from age, height, weight, or the other SNPs studied, and no association was found with the other polymorphisms. Age and history of preeclampsia were also identified as risk factors. The presence of at least one polymorphic allele for NOS3 T-786C was also associated with the occurrence of eclampsia or HELLP syndrome among preeclamptic women. Conclusions Our data support that the NOS3 T-786C SNP is associated with preeclampsia and the severity of its complications. PMID:26317342

Background The fidelity of DNA replication serves as the nidus for both genetic evolution and genomic instability fostering disease. Single nucleotidepolymorphisms (SNPs) constitute greater than 80% of the genetic variation between individuals. A new theory regarding DNA replication fidelity has emerged in which selectivity is governed by base-pair geometry through interactions between the selected nucleotide, the complementary strand, and the polymerase active site. We hypothesize that specific nucleotide combinations in the flanking regions of SNP fragments are associated with mutation. Results We modeled the relationship between DNA sequence and observed polymorphisms using the novel multifactor dimensionality reduction (MDR) approach. MDR was originally developed to detect synergistic interactions between multiple SNPs that are predictive of disease susceptibility. We initially assembled data from the Broad Institute as a pilot test for the hypothesis that flanking region patterns associate with mutagenesis (n = 2194). We then confirmed and expanded our inquiry with human SNPs within coding regions and their flanking sequences collected from the National Center for Biotechnology Information (NCBI) database (n = 29967) and a control set of sequences (coding region) not associated with SNP sites randomly selected from the NCBI database (n = 29967). We discovered seven flanking region pattern associations in the Broad dataset which reached a minimum significance level of p ≤ 0.05. Significant models (p << 0.001) were detected for each SNP type examined in the larger NCBI dataset. Importantly, the flanking region models were elongated or truncated depending on the nucleotide change. Additionally, nucleotide distributions differed significantly at motif sites relative to the type of variation observed. The MDR approach effectively discerned specific sites within the flanking regions of observed SNPs and their respective identities, supporting the collective

Type 2 diabetes (T2D) is one of the most frequent mortality causes in western countries, with rapidly increasing prevalence. Anti-diabetic drugs are the first therapeutic approach, although many patients develop drug resistance. Most drug responsiveness variability can be explained by genetic causes. Inter-individual variability is principally due to single nucleotidepolymorphisms, and differential drug responsiveness has been correlated to alteration in genes involved in drug metabolism (CYP2C9) or insulin signaling (IRS1, ABCC8, KCNJ11 and PPARG). However, most genome-wide association studies did not provide clues about the contribution of DNA variations to impaired drug responsiveness. Thus, characterizing T2D drug responsiveness variants is needed to guide clinicians toward tailored therapeutic approaches. Here, we extensively investigated polymorphisms associated with altered drug response in T2D, predicting their effects in silico. Combining different computational approaches, we focused on the expression pattern of genes correlated to drug resistance and inferred evolutionary conservation of polymorphic residues, computationally predicting the biochemical properties of polymorphic proteins. Using RNA-Sequencing followed by targeted validation, we identified and experimentally confirmed that two nucleotide variations in the CAPN10 gene—currently annotated as intronic—fall within two new transcripts in this locus. Additionally, we found that a Single NucleotidePolymorphism (SNP), currently reported as intergenic, maps to the intron of a new transcript, harboring CAPN10 and GPR35 genes, which undergoes non-sense mediated decay. Finally, we analyzed variants that fall into non-coding regulatory regions of yet underestimated functional significance, predicting that some of them can potentially affect gene expression and/or post-transcriptional regulation of mRNAs affecting the splicing. PMID:27347941

The availability of dense single nucleotidepolymorphism (SNP) genotypes for dairy cattle has created exciting research opportunities and revolutionized practical breeding programs. Broader application of this technology will lead to situations in which genotypes from different low-, medium-, or hig...

Conclusions: Taxodium distichum had significantly higher nucleotide variation than C. japonica, and its patterns of polymorphism contrasted strikingly with those of the latter, which previously has been inferred to have experienced a reduction in population size.

Single nucleotidepolymorphisms (SNPs) are the most abundant form of DNA polymorphism. These polymorphisms can be used in plants as simple genetic markers for many breeding applications, for population studies, and for germplasm fingerprinting. The great increase in the available DNA sequences in the databases has made it possible to identify SNPs by "database mining", and the single most important factor preventing their widespread use appears to be the genotyping cost. Many genotyping platforms rely on the use of sophisticated, automated equipment coupled to costly chemistry and detection systems. A simple and economical method involving a single PCR is reported here for barley SNP genotyping. Using the tetra-primer ARMS-PCR procedure, we have been able to assay unambiguously five SNPs in a set of 132 varieties of cultivated barley. The results show the reliability of this technique and its potential for use in low- to moderate-throughput situations; the association of agronomically important traits is discussed. PMID:15060595

Intraspecific nucleotidepolymorphism in the drought induced transcription factor CBF4 region of Arabidopsis thaliana was analyzed with 17 core accessions growing in different ecoclimate. High density of single nucleotidepolymorphism (SNP) and insertion/deletion (Indel) were found, on average 1 SNP per 35.8 bp and 1 Indel per 143 bp. Nucleotidepolymorphism in non-coding region was three times higher than that in coding region. In coding region of CBF4, SNP frequency is one SNP per 96.4 bp, one nonsynonymous mutation was detected from 25 av, 203 av and 244 av accessions, which is the 205th site amino acid variation: gly val caused by the 1034th site (corresponding to 19,696 site nucleotide of GenBank No. AB015478 as 1) nucleotide variation: G T. Statistical result of nucleotide diversity showed that linkage disequilibrium (LD) existed in large-scale region of CBF4 and recombination event was also detected in 5' non-coding region. Identical to the results of other genes of Arabidopsis, different regions of the gene were seemingly under different selective pressures. Balancing selection resulted in high nucleotide diversity in 3' non-coding region, and the neutral mutation hypothesis can explain the DNA polymorphism in coding region, whereas, nature positive selection in the population affected nucleotide variation in 5' non-coding region of gene. PMID:15633649

Common genetic polymorphisms may explain a portion of the heritable risk for common diseases. Within candidate genes, the number of common polymorphisms is finite, but direct assay of all existing common polymorphism is inefficient, because genotypes at many of these sites are strongly correlated. Thus, it is not necessary to assay all common variants if the patterns of allelic association between common variants can be described. We have developed an algorithm to select the maximally informative set of common single-nucleotidepolymorphisms (tagSNPs) to assay in candidate-gene association studies, such that all known common polymorphisms either are directly assayed or exceed a threshold level of association with a tagSNP. The algorithm is based on the r2 linkage disequilibrium (LD) statistic, because r2 is directly related to statistical power to detect disease associations with unassayed sites. We show that, at a relatively stringent r2 threshold (r2>0.8), the LD-selected tagSNPs resolve >80% of all haplotypes across a set of 100 candidate genes, regardless of recombination, and tag specific haplotypes and clades of related haplotypes in nonrecombinant regions. Thus, if the patterns of common variation are described for a candidate gene, analysis of the tagSNP set can comprehensively interrogate for main effects from common functional variation. We demonstrate that, although common variation tends to be shared between populations, tagSNPs should be selected separately for populations with different ancestries. PMID:14681826

Methotrexate (MTX) is a commonly used disease-modifying antirheumatic drug in rheumatoid arthritis (RA). Polymorphisms occur in several genes encoding key enzymes in the folic acid pathway, which is influenced by MTX, but have not been evaluated in patients with RA. The effect of race on allele frequency has also not been evaluated. In this study, the allele frequencies of polymorphisms in six key enzymes in the MTX-folate pathway in patients with RA and healthy controls, including several common racial groups were studied. European- and African-American patients with RA and European and African healthy controls were genotyped for 22 genetic loci in six genes in the MTX cellular pathway. Differences in genotype distributions between the different racial groups were evaluated using chi(2) tests. Allele frequencies were significantly different (p < 0.001) for eight single nucleotidepolymorphisms between the European and African controls. The allele frequencies of two polymorphisms showed significant differences (p < 0.001) between the African- and European-American patients with RA. Thus, racial differences exist between the allele frequencies of several polymorphisms in enzymes in the MTX-folate pathway in patients with RA and healthy controls. Whether such differences contribute to a differential response to MTX in patients with RA deserves to be investigated. PMID:15212592

Zhikong scallop ( Chlamys farreri) is an important maricultured species in China. Many researches on this species, such as population genetics and QTL fine-mapping, need a large number of molecular markers. In this study, based on the expressed sequence tags (EST), a total of 300 putative single nucleotidepolymorphisms (SNPs) were selected and validated using high resolution melting (HRM) technology with unlabeled probe. Of them, 101 (33.7%) were found to be polymorphic in 48 individuals from 4 populations. Further evaluation with 48 individuals from Qingdao population showed that all the polymorphic loci had two alleles with the minor allele frequency ranged from 0.046 to 0.500. The observed and expected heterozygosities ranged from 0.000 to 0.925 and from 0.089 to 0.505, respectively. Fifteen loci deviated significantly from Hardy-Weinberg equilibrium and significant linkage disequilibrate was detected in one pair of markers. BLASTx gave significant hits for 72 of the 101 polymorphic SNP-containing ESTs. Thirty four polymorphic SNP loci were predicted to be non-synonymous substitutions as they caused either the change of codons (33 SNPs) or pretermination of translation (1 SNP). The markers developed can be used for the population studies and genetic improvement on Zhikong scallop.

Single nucleotidepolymorphisms (SNPs) in the human genome are DNA sequence variations that can alter an individual's response to environmental exposure. SNPs in gene coding regions can lead to changes in the biological properties of the encoded protein. In contrast, SNPs in non-coding gene regulatory regions may affect gene expression levels in an allele-specific manner, and these functional polymorphisms represent an important but relatively unexplored class of genetic variation. The main challenge in analyzing these SNPs is a lack of robust computational and experimental methods. Here, we first outline mechanisms by which genetic variation can impact gene regulation, and review recent findings in this area; then, we describe a methodology for bioinformatic discovery and functional analysis of regulatory SNPs in cis-regulatory regions using the assembled human genome sequence and databases on sequence polymorphism and gene expression. Our method integrates SNP and gene databases and uses a set of computer programs that allow us to: (1) select SNPs, from among the >9 million human SNPs in the NCBI dbSNP database, that are similar to cis-regulatory element (RE) consensus sequences; (2) map the selected dbSNP entries to the human genome assembly in order to identify polymorphic REs near gene start sites; (3) prioritize the candidate polymorphic RE containing genes by searching the existing genotype and gene expression data sets. The applicability of this system has been demonstrated through studies on p53 responsive elements and is being extended to additional pathways and environmentally responsive genes.

Within a polyembryonic mango seedling tree population, the genetic background of individuals should be identical because vigorous plants for cultivation are expected to develop from nucellar embryos representing maternal clones. Due to the fact that the mango cultivar 'Hôi' is assigned to the polyembryonic ecotype, an intra-cultivar variability of ethylene receptor genes was unexpected. Ethylene receptors in plants are conserved, but the number of receptors or receptor isoforms is variable regarding different plant species. However, it is shown here that the ethylene receptor MiETR1 is present in various isoforms within the mango cultivar 'Hôi'. The investigation of single nucleotidepolymorphisms revealed that different MiETR1 isoforms can not be discriminated simply by individual single nucleotide exchanges but by the specific arrangement of single nucleotidepolymorphisms at certain positions in the exons of MiETR1. Furthermore, an MiETR1 isoform devoid of introns in the genomic sequence was identified. The investigation demonstrates some limitations of high resolution melting and ScreenClust analysis and points out the necessity of sequencing to identify individual isoforms and to determine the variability within the tree population. PMID:27093244

Infections by Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) are the predominant cause of bloody diarrhea and hemolytic uremic syndrome in the United States. In silico comparison of the two complete STEC O157 genomes (Sakai and EDL933) revealed a strikingly high level of sequence identity in orthologous protein-coding genes, limiting the use of nucleotide sequences to study the evolution and epidemiology of this bacterial pathogen. To systematically examine single nucleotidepolymorphisms (SNPs) at a genome scale, we designed comparative genome sequencing microarrays and analyzed 1199 chromosomal genes (a total of 1,167,948 bp) and 92,721 bp of the large virulence plasmid (pO157) of eleven outbreak-associated STEC O157 strains. We discovered 906 SNPs in 523 chromosomal genes and observed a high level of DNA polymorphisms among the pO157 plasmids. Based on a uniform rate of synonymous substitution for Escherichia coli and Salmonella enterica (4.7 × 10−9 per site per year), we estimate that the most recent common ancestor of the contemporary β-glucuronidase-negative, non-sorbitolfermenting STEC O157 strains existed ca. 40 thousand years ago. The phylogeny of the STEC O157 strains based on the informative synonymous SNPs was compared to the maximum parsimony trees inferred from pulsed-field gel electrophoresis and multilocus variable numbers of tandem repeats analysis. The topological discrepancies indicate that, in contrast to the synonymous mutations, parts of STEC O157 genomes have evolved through different mechanisms with highly variable divergence rates. The SNP loci reported here will provide useful genetic markers for developing high-throughput methods for fine-resolution genotyping of STEC O157. Functional characterization of nucleotidepolymorphisms should shed new insights on the evolution, epidemiology, and pathogenesis of STEC O157 and related pathogens. PMID:16606700

We describe a genetic variation map for the chicken genome containing 2.8 million single nucleotidepolymorphisms (SNPs), based on a comparison of the sequences of 3 domestic chickens (broiler, layer, Silkie) to their wild ancestor Red Jungle Fowl (RJF). Subsequent experiments indicate that at least 90% are true SNPs, and at least 70% are common SNPs that segregate in many domestic breeds. Mean nucleotide diversity is about 5 SNP/kb for almost every possible comparison between RJF and domestic lines, between two different domestic lines, and within domestic lines--contrary to the idea that domestic animals are highly inbred relative to their wild ancestors. In fact, most of the SNPs originated prior to domestication, and there is little to no evidence of selective sweeps for adaptive alleles on length scales of greater than 100 kb.

Certain genetic polymorphisms have been suggested to be associated with cerebral palsy; the candidate genes are involved in thrombophilia, inflammation and preterm labor, but the mechanism remains to be elucidated. The aim of the present study was to investigate the associations between selected single-nucleotidepolymorphisms (SNPs) and cerebral palsy among children. A case-control study was conducted, including 74 infants with cerebral palsy (case group) and 99 healthy infants (control group). The distributions of the allele and genotype frequencies were examined for the total cerebral palsy patient population in addition to subgroups divided according to gestational age (preterm versus full-term). The results showed that the rs1042714 variant in adrenergic receptor β-2 (ADRB2) and heterozygosity for ADRB2 were associated with the cerebral palsy risk among the preterm infants. No significant differences in the allele or genotype frequencies were observed between the total cerebral palsy patient population and controls for the eight SNPs investigated. PMID:26623029

Protein Z has been reported to exert an important role in inhibiting coagulation. Polymorphisms in the protein Z gene (PROZ) may affect protein Z levels and thus play a role in thrombosis. This study aimed to investigate the prevalence and clinical significance of protein Z gene G79A polymorphism in Egyptian patients with systemic lupus erythematosus (SLE). We studied the distribution of the protein Z gene (rs17882561) (G79A) single-nucleotidepolymorphism by PCR-restriction fragment length polymorphism in 100 Egyptian patients with SLE and 100 age, sex, and ethnically matched controls. There was no statistically significant difference in the distribution of the genotypes between SLE patients and the control group in our study (P = 0.103). But a statistically significant difference in the frequency of the alleles between SLE patients and controls was observed (P = 0.024). Also a significant association was detected between protein Z genotypes (and also A allele) and thrombosis, which is one of the manifestations of SLE (P = 0.004 and P = 0.001, respectively). Moreover, we observed a significant association between the protein Z AA and GA genotypes (and also A allele) and the presence of anticardiolipin antibodies (P = 0.016 and P = 0.004, respectively). The minor A allele of the G79A polymorphism in the protein Z gene might contribute to the genetic susceptibility of SLE in Egyptian patients. Also, an influence for this polymorphism on some of the disease manifestations has been elucidated, so protein Z G79A AG/AA may be a risk factor for thrombosis. PMID:26761586

The pinewood nematode, Bursaphelenchus xylophilus, is native to North America but it only causes damaging pine wilt disease in those regions of the world where it has been introduced. The accurate detection of the species and its dispersal routes are thus essential to define effective control measures. The main goals of this study were to analyse the genetic diversity among B. xylophilus isolates from different geographic locations and identify single nucleotidepolymorphism (SNPs) markers for geographic origin, through a comparative transcriptomic approach. The transcriptomes of seven B. xylophilus isolates, from Continental Portugal (4), China (1), Japan (1) and USA (1), were sequenced in the next generation platform Roche 454. Analysis of effector gene transcripts revealed inter-isolate nucleotide diversity that was validated by Sanger sequencing in the genomic DNA of the seven isolates and eight additional isolates from different geographic locations: Madeira Island (2), China (1), USA (1), Japan (2) and South Korea (2). The analysis identified 136 polymorphic positions in 10 effector transcripts. Pairwise comparison of the 136 SNPs through Neighbor-Joining and the Maximum Likelihood methods and 5-mer frequency analysis with the alignment-independent bilinear multivariate modelling approach correlated the SNPs with the isolates geographic origin. Furthermore, the SNP analysis indicated a closer proximity of the Portuguese isolates to the Korean and Chinese isolates than to the Japanese or American isolates. Each geographic cluster carried exclusive alleles that can be used as SNP markers for B. xylophilus isolate identification. PMID:24391785

The pinewood nematode, Bursaphelenchus xylophilus, is native to North America but it only causes damaging pine wilt disease in those regions of the world where it has been introduced. The accurate detection of the species and its dispersal routes are thus essential to define effective control measures. The main goals of this study were to analyse the genetic diversity among B. xylophilus isolates from different geographic locations and identify single nucleotidepolymorphism (SNPs) markers for geographic origin, through a comparative transcriptomic approach. The transcriptomes of seven B. xylophilus isolates, from Continental Portugal (4), China (1), Japan (1) and USA (1), were sequenced in the next generation platform Roche 454. Analysis of effector gene transcripts revealed inter-isolate nucleotide diversity that was validated by Sanger sequencing in the genomic DNA of the seven isolates and eight additional isolates from different geographic locations: Madeira Island (2), China (1), USA (1), Japan (2) and South Korea (2). The analysis identified 136 polymorphic positions in 10 effector transcripts. Pairwise comparison of the 136 SNPs through Neighbor-Joining and the Maximum Likelihood methods and 5-mer frequency analysis with the alignment-independent bilinear multivariate modelling approach correlated the SNPs with the isolates geographic origin. Furthermore, the SNP analysis indicated a closer proximity of the Portuguese isolates to the Korean and Chinese isolates than to the Japanese or American isolates. Each geographic cluster carried exclusive alleles that can be used as SNP markers for B. xylophilus isolate identification. PMID:24391785

We report a low-cost test, based on gold nanoparticles, for the colorimetric (naked-eye) fingerprinting of a panel of single nucleotidepolymorphisms (SNPs), relevant for the personalized therapy of psoriasis. Such pharmacogenomic tests are not routinely performed on psoriasis patients, due to the high cost of standard technologies. We demonstrated high sensitivity and specificity of our colorimetric test by validating it on a cohort of 30 patients, through a double-blind comparison with two state-of-the-art instrumental techniques, namely reverse dot blotting and sequencing, finding 100% agreement. This test offers high parallelization capabilities and can be easily generalized to other SNPs of clinical relevance, finding broad utility in diagnostics and pharmacogenomics.We report a low-cost test, based on gold nanoparticles, for the colorimetric (naked-eye) fingerprinting of a panel of single nucleotidepolymorphisms (SNPs), relevant for the personalized therapy of psoriasis. Such pharmacogenomic tests are not routinely performed on psoriasis patients, due to the high cost of standard technologies. We demonstrated high sensitivity and specificity of our colorimetric test by validating it on a cohort of 30 patients, through a double-blind comparison with two state-of-the-art instrumental techniques, namely reverse dot blotting and sequencing, finding 100% agreement. This test offers high parallelization capabilities and can be easily generalized to other SNPs of clinical relevance, finding broad utility in diagnostics and pharmacogenomics. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02200f

The sensitive identification of single nucleotidepolymorphisms becomes increasingly important for disease diagnosis, prevention, and practical applicability of pharmacogenomics. Herein, we propose a simple, highly selective, label-free single nucleotidepolymorphisms (SNPs) sensing device by electrochemically monitoring the diffusion flux of ferricyanide probe across probe DNA/morpholino duplex functionalized nanochannels of porous anodic alumina. When perfectly matched or mismatched target DNA flows through the nanochannels modified with probe DNA/morpholino duplex, it competes for the probe DNA from morpholino, resulting in a change of the surface charges. Thus, the diffusion flux of negatively charged electroactive probe ferricyanide is modulated since it is sensitive to the surface charge due to the electrostatic interactions in electric double layer-merged nanochannels. Monitoring of the change in diffusion flux of probe enables us to detect not only a single base or two base mismatched sequence but also the specific location of the mismatched base. As is demonstrated, SNPs in the PML/RARα fusion gene, known as a biomarker of acute promyelocytic leukemia (APL), have been successfully detected. PMID:25734499

A label-free DNA and single nucleotidepolymorphism (SNP) sensing method is described. It is based on the use of the pseudodielectric function of gallium plasmonic nanoparticles (GaNPs) deposited on Si (100) substrates under reversal of the polarization handedness condition. Under this condition, the pseudodielectric function is extremely sensitive to changes in the surrounding medium of the nanoparticle surface providing an excellent sensing platform competitive to conventional surface plasmon resonance. DNA sensing has been carried out by immobilizing a thiolated capture probe sequence from Helicobacter pylori onto GaNP/Si substrates; complementary target sequences of Helicobacter pylori can be quantified over the range of 10 pM to 3.0 nM with a detection limit of 6.0 pM and a linear correlation coefficient of R(2) = 0.990. The selectivity of the device allows the detection of a single nucleotidepolymorphism (SNP) in a specific sequence of Helicobacter pylori, without the need for a hybridization suppressor in solution such as formamide. Furthermore, it also allows the detection of this sequence in the presence of other pathogens, such as Escherichia coli in the sample. The broad applicability of the system was demonstrated by the detection of a specific gene mutation directly associated with cystic fibrosis in large genomic DNA isolated from blood cells. PMID:27120517

Porcine beta-defensin-1 (PBD-1) gene plays an important role in the innate immunity of pigs. The peptide encoded by this gene is an antimicrobial peptide that has direct activity against a wide range of microbes. This peptide is involved in the co-creation of an antimicrobial barrier in the oral cavity of pigs. The objective of the present study was to detect polymorphisms, if any, in exon-1 and exon-2 regions of PBD-1 gene in Large White Yorkshire (LWY) and native Ankamali pigs of Kerala, India. Blood samples were collected from 100 pigs and genomic DNA was isolated using phenol chloroform method. The quantity of DNA was assessed in a spectrophotometer and quality by gel electrophoresis. Exon-1 and exon-2 regions of PBD-1 gene were amplified by polymerase chain reaction (PCR) and the products were subjected to single strand conformation polymorphism (SSCP) analysis. Subsequent silver staining of the polyacrylamide gels revealed three unique SSCP banding patterns in each of the two exons. The presence of single nucleotidepolymorphisms (SNPs) was confirmed by nucleotide sequencing of the PCR products. A novel SNP was found in the 5'-UTR region of exon-1 and a SNP was detected in the mature peptide coding region of exon-2. In exon-1, the pooled population frequencies of GG, GT, and TT genotypes were 0.67, 0.30, and 0.03, respectively. GG genotype was predominant in both the breeds whereas TT genotype was not detected in LWY breed. Similarly, in exon-2, the pooled population frequencies of AA, AG, and GG genotypes were 0.50, 0.27, and 0.23, respectively. AA genotype was predominant in LWY pigs whereas GG genotype was predominant in native pigs. These results suggest that there exists a considerable genetic variation at PBD-1 locus and further association studies may help in development of a PCR based genotyping test to select pigs with better immunity. PMID:26950860

Porcine beta-defensin-1 (PBD-1) gene plays an important role in the innate immunity of pigs. The peptide encoded by this gene is an antimicrobial peptide that has direct activity against a wide range of microbes. This peptide is involved in the co-creation of an antimicrobial barrier in the oral cavity of pigs. The objective of the present study was to detect polymorphisms, if any, in exon-1 and exon-2 regions of PBD-1 gene in Large White Yorkshire (LWY) and native Ankamali pigs of Kerala, India. Blood samples were collected from 100 pigs and genomic DNA was isolated using phenol chloroform method. The quantity of DNA was assessed in a spectrophotometer and quality by gel electrophoresis. Exon-1 and exon-2 regions of PBD-1 gene were amplified by polymerase chain reaction (PCR) and the products were subjected to single strand conformation polymorphism (SSCP) analysis. Subsequent silver staining of the polyacrylamide gels revealed three unique SSCP banding patterns in each of the two exons. The presence of single nucleotidepolymorphisms (SNPs) was confirmed by nucleotide sequencing of the PCR products. A novel SNP was found in the 5′-UTR region of exon-1 and a SNP was detected in the mature peptide coding region of exon-2. In exon-1, the pooled population frequencies of GG, GT, and TT genotypes were 0.67, 0.30, and 0.03, respectively. GG genotype was predominant in both the breeds whereas TT genotype was not detected in LWY breed. Similarly, in exon-2, the pooled population frequencies of AA, AG, and GG genotypes were 0.50, 0.27, and 0.23, respectively. AA genotype was predominant in LWY pigs whereas GG genotype was predominant in native pigs. These results suggest that there exists a considerable genetic variation at PBD-1 locus and further association studies may help in development of a PCR based genotyping test to select pigs with better immunity. PMID:26950860

There are two regulatory single nucleotidepolymorphisms (rSNPs) at the beginning of the second intron of the mouse K-ras gene that are strongly associated with lung cancer susceptibility. We performed functional analysis of three SNPs (rs12228277: T greater than A, rs12226937: G greater than A, and rs61761074: T greater than G) located in the same region of human KRAS. We found that rs12228277 and rs61761074 result in differential binding patterns of lung nuclear proteins to oligonucleotide probes corresponding two alternative alleles; in both cases, the transcription factor NF-Y is involved. G greater than A substitution (rs12226937) had no effect on the binding of lung nuclear proteins. However, all the nucleotide substitutions under study showed functional effects in a luciferase reporter assay. Among them, rs61761074 demonstrated a significant correlation with allele frequency in non-small-cell lung cancer (NSCLC). Taken together, the results of our study suggest that a T greater than G substitution at nucleotide position 615 in the second intron of the KRAS gene (rs61761074) may represent a promising genetic marker of NSCLC. PMID:26648033

DNA mutation binding proteins alone and as chimeric proteins with nucleases are used with solid supports to detect DNA sequence variations, DNA mutations and single nucleotidepolymorphisms. The solid supports may be flow cytometry beads, DNA chips, glass slides or DNA dips sticks. DNA molecules are coupled to solid supports to form DNA-support complexes. Labeled DNA is used with unlabeled DNA mutation binding proteins such at TthMutS to detect DNA sequence variations, DNA mutations and single nucleotide length polymorphisms by binding which gives an increase in signal. Unlabeled DNA is utilized with labeled chimeras to detect DNA sequence variations, DNA mutations and single nucleotide length polymorphisms by nuclease activity of the chimera which gives a decrease in signal.

Oral lichen planus (OLP) is an intractable, chronic inflammatory disorder, and its pathogenesis is still largely unknown. Some literatures supported that genes involved in both oxidative stress and prostaglandin metabolism play an important role in the process of inflammation. To explore their association with OLP, we investigated four single nucleotidepolymorphisms (SNPs) from myeloperoxidase (MPO) and cyclooxygenase (COX) genes in 475 Chinese individuals (242 case and 233 controls) by MassArray. Although the genotype distributions had no significant differences between the patients and controls, we found that in different gender, rs2243828 from MPO displayed the statistically significant variance genotype frequencies between patients and controls (P = 0.018 in females, P = 0.035 in males). Moreover, for the major allele recessive model, this SNP also showed a significant difference between case and control groups in males (P = 0.015). In this study, we first observed significant association with MPO polymorphism and OLP risk in different gender groups in Chinese, suggesting MPO polymorphism is a gender-specific risk factor of OLP probably by influencing sex hormone-sensitive elements to regulate inflammatory gene expression networks, and we further revealed that oxidative stress was actually involved in the pathogenesis of this disease. Moreover, these findings inspire us some constructive solutions to the treatment of this disease. PMID:25823564

ABSTRACT We had investigated whether sequence variants within DKK3 gene are associated with the development of prostate cancer in a Korean study cohort. We evaluated the association between 53 single nucleotidepolymorphisms (SNPs) in the DKK3 gene and prostate cancer risk as well as clinical characteristics (PSA, clinical stage, pathological stage and Gleason score) in Korean men (272 prostate cancer subjects and 173 benign prostate hyperplasia subjects) using unconditional logistic regression analysis. Of the 53 SNPs and 25 common haplotypes, 5 SNPs and 4 haplotypes were associated with prostate cancer risk (P=0.02–0.04); 3 SNPs and 2 haplotypes were significantly associated with susceptibility to prostate cancer, however 2 SNPs and 2 haplotypes exhibited a significant protective effect on prostate cancer. Logistic analyses of the DKK3 gene polymorphisms with several prostate cancer related factors showed that several SNPs were significant; three SNPs and two haplotypes to PSA level, three SNPs and two haplotypes to clinical stage, nine SNPs and two haplotype to pathological stage, one SNP and one haplotypes to Gleason score. To the author's knowledge, this is the first report documenting that DKK3 polymorphisms are not only associated with prostate cancer but also related to prostate cancer-related factors. PMID:26689513

The BARX genes 1 and 2 are Bar class homeobox genes expressed in craniofacial structures during development. In this report, we present the genomic structure, chromosomal localization, and polymorphic markers in BARX2. The gene has four exons, ranging in size from 85 to 1099 bp. BARX2 is localized on human chromosome 11q25, as determined by radiation hybrid mapping. In the mouse, Barx2 is coexpressed with Pitx2 in several tissues. Based on the coexpression, BARX2 was assumed to be a candidate gene for those cases of Rieger syndrome that cannot be associated with mutations of PITX2. Mutations in PITX2 cause some cases of Rieger syndrome, an autosomal dominant disorder affecting eyes, teeth, and umbilicus. DNA from Rieger patients was subjected to single-strand conformation polymorphism screening of the BARX2 coding region. Three single nucleotidepolymorphisms were found in a normal population, although no etiologic mutations were detectable in over 100 cases of Rieger syndrome or in individuals with related ocular disorders. PMID:10644443

The oil palm is a tropical oil bearing tree. Recently EST-derived SNPs and SSRs are a free by-product of the currently expanding EST (Expressed Sequence Tag) data bases. The development of high-throughput methods for the detection of SNPs (Single NucleotidePolymorphism) and small indels (insertion / deletion) has led to a revolution in their use as molecular markers. Available (5452) Oil palm EST sequences were mined from dbEST of NCBI. CAP3 program was used to assemble EST sequences into contigs. Candidate SNPs and Indel polymorphisms were detected using the perl script auto_snip version 1.0 which has used 576 ESTs for detecting SNPs and Indel sites. We found 1180 SNP sites and 137 indel polymorphisms with frequency 1.36 SNPs / 100 bp. Among the six tissues from which the EST libraries had been generated, mesocarp had high frequency of 2.91 SNPs and indels per 100 bp whereas the zygotic embryos had lowest frequency of 0.15 per 100 bp. We also used the Shannon index to analyze the proportion of ten possible types of SNP/indels. ESTs from tissues of normal apex showed highest values of Shannon index (0.60) whereas abnormal apex had least value (0.02). The present report deals the use of Shannon index for comparing SNP/ indel frequencies mined from ESTlibraries and also confirm that the frequency of SNP occurrence in oil palm to use them as markers for genetic studies. PMID:21670789

Multiple genetic and environmental factors interact to determine an individual's predisposition to non-alcoholic fatty liver disease and its phenotypic characteristics. Association studies have found a number of alleles associated with the development of non-alcoholic steatohepatitis. Our aim was to investigate whether multiple risk-associated alleles may be present in affected monozygotic twins, indicating underlying genetic predisposition to non-alcoholic steatohepatitis. We determined the genotype of 14 candidate gene polymorphisms (at 11 unlinked loci) in a set of monozygotic twins who presented with cirrhosis within 18 months of each other. Genotyping revealed multiple single nucleotidepolymorphisms at 9 independent loci in genes PNPLA3, APOC3, GCKR, TRIB1, LYPLAL1, PPP1R3B, COL13A1, and EFCAB4B, previously implicated in contributing to non-alcoholic steatohepatitis pathogenesis. In conclusion, this case series illustrates the potential cumulative effect of multiple polymorphisms in the development and potential progression of a complex trait such as NASH cirrhosis. PMID:26845607

The MBL1 and MBL2 genes encode mannan-binding lectins (MBL) A and C, respectively, that are collagenous lectins (collectins) produced mainly by the liver. Several single-nucleotidepolymorphisms (SNPs) in the human MBL2 gene are responsible for various innate immune dysfunctions due to abnormal structure or expression of human MBL-C. The MBL1 gene encodes MBL-A, which has bacteria-binding properties in pigs and rodents but is mutated to a pseudogene in humans and chimpanzees. In these studies, we surveyed both porcine MBL genes for SNPs that might impair disease resistance. Single-strand conformational polymorphism (SSCP) analysis of MBL cDNAs from porcine liver revealed three SNPs within the coding region of MBL1 in various breeds of pigs. One nonsynonymous SNP that substituted cysteine for glycine in the collagen-like domain of pig MBL-A was found by a multiplex PCR test in all European pig breeds examined, with allele frequencies ranging from 1.4 to 46.4%. No SNPs were identified in the coding region of porcine MBL2 but the expression of MBL-C in the liver was widely variable in comparison to the expression of MBL-A, GAPDH, PigMAP, and haptoglobin. These results indicate that some pigs have a miscoding defect in MBL-A and a possible expression defect in MBL-C, which are analogous to coding and promoter polymorphisms that affect human MBL-C. PMID:17089118

The episialin gene (MUC1) encodes an epithelial mucin containing a variable number of repeats with a length of twenty amino acids, resulting in many different alleles that can be subdivided into two size classes. The episialin pre-mRNA uses either one of two neighbouring splice acceptor sites for exon 2, which mainly encodes the repeats. Using the genetic polymorphism of the episialin gene to identify different alleles, we show here that the splice site recognition is allele dependent and is based on a single A/G nucleotide difference in exon 2 eight nucleotides downstream of the second splice acceptor site. Transfection experiments confirm that this polymorphicnucleotide regulates the splice site selection. The identity of this nucleotide is in most cases correlated with one of the size classes of the alleles, indicating that mutations altering the number of repeats seldom arise by unequal cross-over between the repeat regions. Images PMID:2014168

Preeclampsia is a pregnancy specific disorder and a risk factor for later cardiovascular disease. The cause and detailed pathophysiology remains unknown. G protein signaling is involved in a variety of physiological processes, including blood pressure regulation. We assessed whether distributions of 3 single nucleotidepolymorphisms in genes coding for components of G protein signaling pathways that have been associated with hypertension differ between women with preeclampsia and normotensive pregnant women; the G protein β3 subunit gene (GNB3) C825T polymorphism (rs5443), the angiotensin II type 1 receptor gene (AGTR1) 3'UTR A1166C polymorphism (rs5186), and the regulator of G protein signaling 2 gene (RGS2) 3'UTR C1114G polymorphism (rs4606). Two separate Norwegian study populations were used; a large population based study and a smaller, but clinically well-described pregnancy biobank. A descriptive study of 43 women with eclampsia was additionally included. In the population-based study, an increased odds of preeclampsia (odds ratio, 1.21; [95% confidence interval, 1.05-1.40]; P=0.009) and recurrent preeclampsia (odds ratio, 1.43; [95% confidence interval, 1.06-1.92];, P=0.017) was found in women carrying the rs4606 CG or GG genotype. In early-onset preeclamptic patients with decidual spiral artery biopsies available (n=24), the rs4606 CG or GG genotype was more frequent in those with acute atherosis (resembling early stage of atherosclerosis) compared with those without: odds ratio, 15.0; (95% confidence interval, 2.02-111.2); P=0.004. No association was found between preeclampsia and the rs5443 or the rs5186. The genotype distribution in eclamptic women was not different from preeclamptic women. In conclusion, RGS2 rs4606 may affect the risk and progression of preeclampsia. PMID:23339167

The susceptibility genes for psoriasis remain to be identified. At least one of these must be in the major histocompatibility complex (MHC) to explain associations with alleles at human leucocyte antigen (HLA)-A, -B, -C, -DR, -DQ and C4. In fact, most of these alleles are components of just two ancestral haplotypes (AHs) designated 13.1 and 57.1. Although relevant MHC gene(s) could be within a region of at least 4 Mb, most studies have favoured the area near HLA-B and -C. This region contains a large number of non-HLA genes, many of which are duplicated and polymorphic. Members of one such gene family, PERB11.1 and PERB11.2, are expressed in the skin and are encoded in the region between tumour necrosis factor and HLA-B. To investigate the relationship of PERB11.1 alleles to psoriasis, sequence based typing was performed on 97 patients classified according to age of onset and family history. The frequency of the PERB11.1*06 allele is 44% in type I psoriasis but only 7% in controls (Pc = 0.003 by Fisher's exact test, two-tailed). The major determinant of this association is a single nucleotidepolymorphism (SNP) within intron 4. In normal and affected skin, expression of PERB11 is mainly in the basal layer of the epidermis including ducts and follicles. PERB11 is also present in the upper keratin layers but there is relative deficiency in the intermediate layers. These findings suggest a possible role for PERB11 and other MHC genes in the pathogenesis of psoriasis. PMID:10691930

We have developed an MLST-based scheme for typing Escherichia coli isolates using pyrosequencing of single nucleotidepolymorphic positions (SNP). The SNP sequences are converted into allelic patterns and analyzed using the same approach used for MLST analyses. We have tested the method in two unselected collections of clinical isolates of E. coli obtained from blood and urine cultures. The two collections had a similar structure, 25% of the profiles (representing 68% of the isolates) were common to both, and 62% of the profiles (nearly 20% of the isolates) were unique. The four major profiles accounted for 44% of the isolates, and among these the most frequent one was related to the pandemic ST131 clone. The method is easy to implement and might be useful for typing large microbial collections. PMID:21723423

Toll-like receptors (TLRs) are the best-studied family of pattern-recognition receptors (PRRs), whose task is to rapidly recognize evolutionarily conserved structures on the invading microorganisms. Through binding to these patterns, TLRs trigger a number of proinflammatory and anti-microbial responses, playing a key role in the first line of defence against the pathogens also promoting adaptive immunity responses. Growing amounts of data suggest that single nucleotidepolymorphisms (SNPs) on the various human TLR proteins are associated with altered susceptibility to infection. This review summarizes the role of TLRs in innate immunity, their ligands and signalling and focuses on the TLR SNPs which have been linked to infectious disease susceptibility. PMID:25560985

This report describes a microfluidic solid-phase Chemical Gradient-mediated Melting Curve Analysis (CGMCA) method for single nucleotidepolymorphism (SNP) analysis. The method is based on allele-specific denaturation to discriminate mismatched (MM) from perfectly matched (PM) DNA duplexes upon exposure to linear chemical gradient. PM and MM DNA duplexes conjugated on beads are captured in a microfluidic gradient generator device designed with dams, keeping the beads trapped perpendicular to a gradient generating channel. Two denaturants, formamide and urea, were tested for their ability to destabilize the DNA duplex by competing with Watson-Crick pairing. Upon exposure to the chemical gradient, rapid denaturing profile was monitored in real time using fluorescence microscopy. The results show that the two duplexes exhibit different kinetics of denaturation profiles, enabling discrimination of MM from PM DNA duplexes to score SNP. PMID:19593749

Background The analysis of human Y-chromosome variation in the context of population genetics and forensics requires the genotyping of dozens to hundreds of selected single-nucleotidepolymorphisms (SNPs). In the present study, we developed a 121-plex (121 SNPs in a single array) TaqMan array capable of distinguishing most haplogroups and subhaplogroups on the Y-chromosome human phylogeny in Europe. Results We present data from 264 samples from several European areas and ethnic groups. The array developed in this study shows >99% accuracy of assignation to the Y human phylogeny (with an average call rate of genotypes >96%). Conclusions We have created and evaluated a robust and accurate Y-chromosome multiplex which minimises the possible errors due to mixup when typing the same sample in several independent reactions. PMID:21627798

Pharmacological treatment of several diseases, such as attention-deficit hyperactivity disorder (ADHD), presents marked variability in efficiency and its adverse effects. The genotyping of specific single nucleotidepolymorphisms (SNPs) can support the prediction of responses to drugs and the genetic risk of presenting comorbidities associated with ADHD. This study presents two rapid and affordable microarray-based strategies to discriminate three clinically important SNPs in genes ADRA2A, SL6CA2, and OPRM1 (rs1800544, rs5569, and rs1799971, respectively). These approaches are allele-specific oligonucleotide hybridization (ASO) and a combination of allele-specific amplification (ASA) and solid-phase hybridization. Buccal swab and blood samples taken from ADHD patients and controls were analyzed by ASO, ASA, and a gold-reference method. The results indicated that ASA is superior in genotyping capability and analytical performance. PMID:26832728

The genotypic characterization of Coxiella burnetii provides useful information about the strains circulating at the farm, region, or country level and may be used to identify the source of infection for animals and humans. The aim of the present study was to investigate the strains of C. burnetii circulating in caprine and bovine Belgian farms using a single nucleotidepolymorphism (SNP) technique. Direct genotyping was applied to different samples (bulk tank milk, individual milk, vaginal swab, fetal product, and air sample). Besides the well-known SNP genotypes, unreported ones were found in bovine and caprine samples, increasing the variability of the strains found in the two species in Belgium. Moreover, multiple genotypes were detected contemporarily in caprine farms at different years of sampling and by using different samples. Interestingly, certain SNP genotypes were detected in both bovine and caprine samples, raising the question of interspecies transmission of the pathogen. PMID:26475104

We sequenced from 5'-franking region to intron 1 (to 337 bp downstream from exon 1) of the UDP-glucuronosyltransferase (UGT) 1A9 gene prepared from 55 Japanese cancer patients. Seven single nucleotidepolymorphisms (SNPs) were found. Two of them were UGT1A9 -118(T)n (n=10) and UGT1A9*5, and four were reported SNPs in intron 1 of UGT1A9 gene (89540C>T, 89549G>A, 89616T>A and 89710A>C). A novel SNP (89587T>C) was found. The sequence is as follows: SNP, 050824FujitaK001; Gene Name, UGT1A9; Accession Number, AF297093; Length, 25 bases; 5'-CCTTCTTGAAGAT/CATGTATTTATAA-3'. Two patients were heterozygous for the mutant allele, resulting in the allele frequency of 1.82%. PMID:16547398

Single nucleotidepolymorphisms (SNPs) are widespread in the Nicotiana genome. Using an alignment and variation detection method, we developed 20,607,973 SNPs, based on the expressed sequence tag sequences of 10 Nicotiana species. The replacement rate was much higher than the transversion rate in the SNPs, and SNPs widely exist in the Nicotiana. In vitro verification indicated that all of the SNPs were high quality and accurate. Evolutionary relationships between 15 varieties were investigated by polymerase chain reaction with a special primer; the specific 302 locus of these sequence results clearly indicated the origin of Zhongyan 100. A database of Nicotiana SNPs (NSNP) was developed to store and search for SNPs in Nicotiana. NSNP is a tool for researchers to develop SNP markers of sequence data. PMID:26214460

Detection of single based genetic mutation by using oligonucleotide probes is one of the common methods of detecting single nucleotidepolymorphisms at known loci. In this paper, we demonstrated a hybridization system which included a buffer solution that produced selective salt-induced effect and a locked nucleic acid modified 12 nt oligonucleotide probe. The hybridization system is suitable for hybridization under room temperature. By using magnetic nanoparticles as carriers for PCR products, the SNPs (MDR1 C3435T/A) from 45 volunteers were analyzed, and the results were consistent with the results from pyrophosphoric acid sequencing. The method presented in this paper differs from the traditional method of using molecular beacons to detect SNPs in that it is suitable for research institutions lacking real-time quantitative PCR detecting systems, to detect PCR products at room temperature. PMID:26347880

Reliable population estimates are an important aspect of sustainable wildlife management and conservation but can be difficult to obtain for rare and elusive species. Here, we test a new census method based on pedigree reconstruction recently developed by Creel and Rosenblatt (2013). Using a panel of 96 single-nucleotidepolymorphisms (SNPs), we genotyped fecal samples from two Swedish brown bear populations for pedigree reconstruction. Based on 433 genotypes from central Sweden (CS) and 265 from northern Sweden (NS), the population estimates (N = 630 for CS, N = 408 for NS) fell within the 95% CI of the official estimates. The precision and accuracy improved with increasing sampling intensity. Like genetic capture-mark-recapture methods, this method can be applied to data from a single sampling session. Pedigree reconstruction combined with noninvasive genetic sampling may thus augment population estimates, particularly for rare and elusive species for which sampling may be challenging. PMID:27096081

Screening of the entire human genome using high-density single nucleotidepolymorphism array (SNPA) has become a powerful technique used in cancer genetics and population genetics studies. The GeneChip® Mapping Array, introduced by Affymetrix, is one SNPA platform utilised for genotyping studies. This GeneChip system allows researchers to gain a comprehensive view of cancer biology on a single platform for the quantification of chromosomal amplifications, deletions, and loss of heterozygosity or for allelic imbalance studies. Importantly, this array analysis has the potential to reveal novel genetic findings involved in the multistep development of cancer. Given the importance of genetic factors in leukaemogenesis and the usefulness of screening the whole genome, SNPA analysis has been utilised in many studies to characterise genetic aberrations in childhood acute lymphoblastic leukaemia. PMID:22135543

A label-free DNA and single nucleotidepolymorphism (SNP) sensing method is described. It is based on the use of the pseudodielectric function of gallium plasmonic nanoparticles (GaNPs) deposited on Si (100) substrates under reversal of the polarization handedness condition. Under this condition, the pseudodielectric function is extremely sensitive to changes in the surrounding medium of the nanoparticle surface providing an excellent sensing platform competitive to conventional surface plasmon resonance. DNA sensing has been carried out by immobilizing a thiolated capture probe sequence from Helicobacter pylori onto GaNP/Si substrates; complementary target sequences of Helicobacter pylori can be quantified over the range of 10 pM to 3.0 nM with a detection limit of 6.0 pM and a linear correlation coefficient of R2 = 0.990. The selectivity of the device allows the detection of a single nucleotidepolymorphism (SNP) in a specific sequence of Helicobacter pylori, without the need for a hybridization suppressor in solution such as formamide. Furthermore, it also allows the detection of this sequence in the presence of other pathogens, such as Escherichia coli in the sample. The broad applicability of the system was demonstrated by the detection of a specific gene mutation directly associated with cystic fibrosis in large genomic DNA isolated from blood cells.A label-free DNA and single nucleotidepolymorphism (SNP) sensing method is described. It is based on the use of the pseudodielectric function of gallium plasmonic nanoparticles (GaNPs) deposited on Si (100) substrates under reversal of the polarization handedness condition. Under this condition, the pseudodielectric function is extremely sensitive to changes in the surrounding medium of the nanoparticle surface providing an excellent sensing platform competitive to conventional surface plasmon resonance. DNA sensing has been carried out by immobilizing a thiolated capture probe sequence from Helicobacter pylori

We report a low-cost test, based on gold nanoparticles, for the colorimetric (naked-eye) fingerprinting of a panel of single nucleotidepolymorphisms (SNPs), relevant for the personalized therapy of psoriasis. Such pharmacogenomic tests are not routinely performed on psoriasis patients, due to the high cost of standard technologies. We demonstrated high sensitivity and specificity of our colorimetric test by validating it on a cohort of 30 patients, through a double-blind comparison with two state-of-the-art instrumental techniques, namely reverse dot blotting and sequencing, finding 100% agreement. This test offers high parallelization capabilities and can be easily generalized to other SNPs of clinical relevance, finding broad utility in diagnostics and pharmacogenomics. PMID:27174795

Our previous research establishes that changes of expression of the ATP-binding cassette genes family is connected with the neoadjuvant chemotherapy effect. However, the mechanism of regulation of resistance gene expression remains unclear. As many researchers believe, single nucleotidepolymorphisms can be involved in this process. Thereupon, microarray analysis is used to study polymorphisms in ATP-binding cassette genes. It is thus found that MDR gene expression is connected with 5 polymorphisms, i.e. rs241432, rs241429, rs241430, rs3784867, rs59409230, which participate in the regulation of expression of own genes.

Pineapple (Ananas comosus [L.] Merr.) is the third most important tropical fruit in the world after banana and mango. As a crop with vegetative propagation, genetic redundancy is a major challenge for efficient genebank management and in breeding. Using expressed sequence tag and nucleotide sequences from public databases, we developed 213 single nucleotidepolymorphism (SNP) markers and validated 96 SNPs by genotyping the United States Department of Agriculture - Agricultural Research Service pineapple germplasm collection, maintained in Hilo, Hawaii. The validation resulted in designation of a set of 57 polymorphic SNP markers that revealed a high rate of duplicates in this pineapple collection. Twenty-four groups of duplicates were detected, encompassing 130 of the total 170 A cosmos accessions. The results show that somatic mutation has been the main source of intra-cultivar variations in pineapple. Multivariate clustering and a model-based population stratification suggest that the modern pineapple cultivars are comprised of progenies that are derived from different wild Ananas botanical varieties. Parentage analysis further revealed that both A. comosus var. bracteatus and A. comosus var. ananassoides are likely progenitors of pineapple cultivars. However, the traditional classification of cultivated pineapple into horticultural groups (e.g. ‘Cayenne’, ‘Spanish’, ‘Queen’) was not well supported by the present study. These SNP markers provide robust and universally comparable DNA fingerprints; thus, they can serve as an efficient genotyping tool to assist pineapple germplasm management, propagation of planting material, and pineapple cultivar protection. The high rate of genetic redundancy detected in this pineapple collection suggests the potential impact of applying this technology on other clonally propagated perennial crops. PMID:26640697

Pineapple (Ananas comosus [L.] Merr.) is the third most important tropical fruit in the world after banana and mango. As a crop with vegetative propagation, genetic redundancy is a major challenge for efficient genebank management and in breeding. Using expressed sequence tag and nucleotide sequences from public databases, we developed 213 single nucleotidepolymorphism (SNP) markers and validated 96 SNPs by genotyping the United States Department of Agriculture - Agricultural Research Service pineapple germplasm collection, maintained in Hilo, Hawaii. The validation resulted in designation of a set of 57 polymorphic SNP markers that revealed a high rate of duplicates in this pineapple collection. Twenty-four groups of duplicates were detected, encompassing 130 of the total 170 A cosmos accessions. The results show that somatic mutation has been the main source of intra-cultivar variations in pineapple. Multivariate clustering and a model-based population stratification suggest that the modern pineapple cultivars are comprised of progenies that are derived from different wild Ananas botanical varieties. Parentage analysis further revealed that both A. comosus var. bracteatus and A. comosus var. ananassoides are likely progenitors of pineapple cultivars. However, the traditional classification of cultivated pineapple into horticultural groups (e.g. 'Cayenne', 'Spanish', 'Queen') was not well supported by the present study. These SNP markers provide robust and universally comparable DNA fingerprints; thus, they can serve as an efficient genotyping tool to assist pineapple germplasm management, propagation of planting material, and pineapple cultivar protection. The high rate of genetic redundancy detected in this pineapple collection suggests the potential impact of applying this technology on other clonally propagated perennial crops. PMID:26640697

The economic and ecological importance of the oyster necessitates further research on the molecular mechanisms, which both regulate the commercially important traits of the oyster and help it to survive in the variable marine environment. Single nucleotidepolymorphisms (SNPs) have been widely used to assess genetic variation and identify genes underlying target traits. In addition, high-resolution melting (HRM) analysis is a potentially powerful method for validating candidate SNPs. In this study, we adopted a rapid and efficient pipeline for the screening and validation of SNPs in the genic region of Crassostrea gigas based on transcriptome sequencing and HRM analysis. Transcriptomes of three wild oyster populations were sequenced using Illumina sequencing technology. In total, 50-60 million short reads, corresponding to 4.5-5.4 Gbp, from each population were aligned to the oyster genome, and 5.8 × 10(5) SNPs were putatively identified, resulting in a predicted SNP every 47 nucleotides on average. The putative SNPs were unevenly distributed in the genome and high-density (≥2%), nonsynonymous coding SNPs were enriched in genes related to apoptosis and responses to biotic stimuli. Subsequently, 1,671 loci were detected by HRM analysis, accounting for 64.7% of the total selected candidate primers, and finally, 1,301 polymorphic SNP markers were developed based on HRM analysis. All of the validated SNPs were distributed into 897 genes and located in 672 scaffolds, and 275 of these genes were stress inducible under unfavourable salinity, temperature, and exposure to air and heavy metals. The validated SNPs in this study provide valuable molecular markers for genetic mapping and characterization of important traits in oysters. PMID:24823694

To estimate a rate for single nucleotide substitutions for maize (Zea mays ssp. mays), we have taken advantage of data from genetic and archaeological studies of the domestication of maize from its wild ancestor, teosinte (Z. mays ssp. parviglumis). Genetic studies have shown that the teosinte branched1 (tb1) gene was a major target of human selection during maize domestication, and sequence diversity in the intergenic region 5' to the tb1-coding sequence is extraordinarily low. We show that polymorphism in this region is consistent with new mutation following fixation for a small number of tb1 haplotypes during domestication. Archeological studies suggest that maize was domesticated approximately 6,250-10,000 years ago and subsequently the size of the maize population is thought to have expanded rapidly. Using the observed number of mutations within the region of selection at tb1, the approximate age of maize domestication, and approximations for the maize genealogy, we have derived estimates for the nucleotide substitution rate for the tb1 intergenic region. Using two approaches, one of which is a coalescent approach, we obtain rate estimates of approximately 2.9 x 10(-8) and 3.3 x 10(-8) substitutions per site per year. We also show that the pattern of polymorphism in the tb1 intergenic region appears to have been strongly affected by the mutagenic effect of DNA methylation. Excluding target sites of symmetric DNA methylation (CG and CNG sites) from analysis, the mutation rate estimates are reduced by approximately 50%-60%, while the rates for CG and CNG sites are nearly an order of magnitude higher. We use rate estimates from the tb1 region to estimate the timing of expansion of transposable elements in the maize genome and suggest that this expansion occurred primarily within the last million years. PMID:16079248

Background Nucleotide excision repair (NER) is a vital response to DNA damage, including damage from tobacco exposure. Single nucleotidepolymorphisms (SNPs) in the NER pathway may encode alterations that affect DNA repair function and therefore influence risk for pancreatic cancer development. Methods A clinic based case-control study in non-Hispanic white persons compared 1,143 patients with pancreatic adenocarcinoma with 1,097 healthy controls. Twenty-seven genes directly and indirectly involved in the NER pathway were identified and 236 tag-SNPs were selected from 26 of these (one had no SNPs identified). Association studies were performed at the gene level by principal components analysis, while recursive partitioning analysis was utilized to identify potential gene-gene and gene-environment interactions within the pathway. At the individual SNP level, adjusted additive, dominant, and recessive models were investigated, and gene-environment interactions were also assessed. Results Gene level analyses showed an association of MMS19L genotype (chromosome 10q24.1) with altered pancreatic cancer risk (p=0.023). Haplotype analysis of MMS19L also showed a significant association (p=0.0132). Analyses of 7 individual SNPs in this gene showed both protective and risk associations for minor alleles, broadly distributed across patient subgroups defined by smoking status, sex, and age. Conclusion In a candidate pathway SNP association study analysis, common variation in a NER gene, MMS19L, was associated with risk for pancreatic cancer. PMID:19318433

Methods to rapidly identify serotypes of Salmonella enterica subspecies I are of vital importance for protecting the safety of food. To supplement the serotyping method dkgB-linked intergenic sequence ribotyping (ISR), single-nucleotidepolymorphisms were characterized within adenylate cyclase (cyaA). The National Center for Biotechnology Information (NCBI) database had 378 cyaA sequences from S. enterica subspecies I, which included 42 unique DNA sequences and 19 different amino acid sequences. Five representative isolates, namely serotypes Typhimurium, Kentucky, Enteritidis phage type PT4, and two variants of Enteritidis phage type PT13a, were differentiated within a microsphere-based fluidics system in cyaA by allele-specific primer extension. Validation against 25 poultry-related environmental Salmonella isolates representing 11 serotypes yielded a ∼89% success rate at identifying the serotype of the isolate, and a different region could be targeted to achieve 100%. When coupled with ISR, all serotypes were differentiated. Phage lineages of serotype Enteritidis 13a and 4 were identified, and a biofilm-forming strain of PT13a was differentiated from a smooth phenotype within phage type. Comparative ranking of mutation indices to genes such as the tRNA transferases, the diguanylate cyclases, and genes used for multilocus sequence typing indicated that cyaA is an appropriate gene for assessing epidemiological trends of Salmonella because of its relative stability in nucleotide composition. PMID:27035032

DNA in biological fluids is often degraded by environmental factors. Given that single nucleotidepolymorphism (SNP) analyses require shorter amplicons than short tandem repeat (STR) analyses do, their use in human identification using degraded samples has recently attracted attention. Although various SNP loci are used to analyze degraded samples, it is unclear which ones are more appropriate. To characterize and identify SNP loci that are susceptible or resistant to degradation, we artificially degraded DNA, obtained from buccal swabs from 11 volunteers, by exposure to ultraviolet (UV) light for different durations (254 nm for 5, 15, 30, 60, or 120 min) and analyzed the resulting SNP loci. DNA degradation was assessed using gel electrophoresis, STR, and SNP profiling. DNA fragmentation occurred within 5 min of UV irradiation, and successful STR and SNP profiling decreased with increasing duration. However, 73% of SNP loci were still detected correctly in DNA samples irradiated for 120 min, a dose that rendered STR loci undetectable. The unsuccessful SNP typing and the base call failure of nucleotides neighboring the SNPs were traced to rs1031825, and we found that this SNP was susceptible to UV light. When comparing the detection efficiencies of STR and SNP loci, SNP typing was more successful than STR typing, making it effective when using degraded DNA. However, it is important to use rs1031825 with caution when interpreting SNP analyses of degraded DNA. PMID:27570235

Abstract Methods to rapidly identify serotypes of Salmonella enterica subspecies I are of vital importance for protecting the safety of food. To supplement the serotyping method dkgB-linked intergenic sequence ribotyping (ISR), single-nucleotidepolymorphisms were characterized within adenylate cyclase (cyaA). The National Center for Biotechnology Information (NCBI) database had 378 cyaA sequences from S. enterica subspecies I, which included 42 unique DNA sequences and 19 different amino acid sequences. Five representative isolates, namely serotypes Typhimurium, Kentucky, Enteritidis phage type PT4, and two variants of Enteritidis phage type PT13a, were differentiated within a microsphere-based fluidics system in cyaA by allele-specific primer extension. Validation against 25 poultry-related environmental Salmonella isolates representing 11 serotypes yielded a ∼89% success rate at identifying the serotype of the isolate, and a different region could be targeted to achieve 100%. When coupled with ISR, all serotypes were differentiated. Phage lineages of serotype Enteritidis 13a and 4 were identified, and a biofilm-forming strain of PT13a was differentiated from a smooth phenotype within phage type. Comparative ranking of mutation indices to genes such as the tRNA transferases, the diguanylate cyclases, and genes used for multilocus sequence typing indicated that cyaA is an appropriate gene for assessing epidemiological trends of Salmonella because of its relative stability in nucleotide composition. PMID:27035032

Background In common bean, expressed sequence tags (ESTs) are an underestimated source of gene-based markers such as insertion-deletions (Indels) or single-nucleotidepolymorphisms (SNPs). However, due to the nature of these conserved sequences, detection of markers is difficult and portrays low levels of polymorphism. Therefore, development of intron-spanning EST-SNP markers can be a valuable resource for genetic experiments such as genetic mapping and association studies. Results In this study, a total of 313 new gene-based markers were developed at target genes. Intronic variation was deeply explored in order to capture more polymorphism. Introns were putatively identified after comparing the common bean ESTs with the soybean genome, and the primers were designed over intron-flanking regions. The intronic regions were evaluated for parental polymorphisms using the single strand conformational polymorphism (SSCP) technique and Sequenom MassARRAY system. A total of 53 new marker loci were placed on an integrated molecular map in the DOR364 × G19833 recombinant inbred line (RIL) population. The new linkage map was used to build a consensus map, merging the linkage maps of the BAT93 × JALO EEP558 and DOR364 × BAT477 populations. A total of 1,060 markers were mapped, with a total map length of 2,041 cM across 11 linkage groups. As a second application of the generated resource, a diversity panel with 93 genotypes was evaluated with 173 SNP markers using the MassARRAY-platform and KASPar technology. These results were coupled with previous SSR evaluations and drought tolerance assays carried out on the same individuals. This agglomerative dataset was examined, in order to discover marker-trait associations, using general linear model (GLM) and mixed linear model (MLM). Some significant associations with yield components were identified, and were consistent with previous findings. Conclusions In short, this study illustrates the power of intron

The objective of this study was to assess the association of single nucleotidepolymorphisms in the thyroglobulin gene, including a previously reported marker in current industry use, with marbling score in beef cattle. Three populations, designated GPE6, GPE7, and GPE8, were studied. The GPE6 pop...

The association of a single nucleotidepolymorphism (SNP) of calpain 1 (CAPN1) gene with shear force of 2.54 cm steaks from M. longissimus dorsi from Gannan yaks (Bos grunniens, n=181) was studied. Yaks were harvested at 2, 3, and 4 yr of age (n=51, 59, and 71, respectively), and samples of each yak...

Accurate identification of individual genotypes in an efficient manner is especially important for cacao (Theobroma cacao L.) germplasm conservation and breeding. The development of single nucleotidepolymorphism (SNP) markers in cacao offers the opportunity to use a high throughput genotyping syste...

Multiplexed single nucleotidepolymorphism (SNP) markers have the potential to increase the speed and cost-effectiveness of genotyping, provided that an optimal SNP density is used for each application. To test the efficiency of multiplexed SNP genotyping for diversity, mapping and breeding applicat...

The highly parallel genotyping assay, such as the GoldenGate assay developed by Illumina, capable of interrogating up to 3,072 single nucleotidepolymorphisms (SNPs) simultaneously, has greatly facilitated the genome-wide studies particularly for crops with large and complex genome structures. In th...

High-density single nucleotidepolymorphism (SNP) genotyping chips are a powerful tool for studying genomic patterns of diversity, inferring ancestral relationships among individuals in populations and studying marker-trait associations in mapping experiments. We developed a genotyping array includ...

While Simple Sequence Repeats (SSRs) are extremely useful genetic markers, recent advances in technology have produced a shift toward use of single nucleotidepolymorphisms (SNPs). The different mutational properties of these two classes of markers result in differences in heterozygosities and allel...

With the low cost of single nucleotidepolymorphism (SNP) discovery, use of SNP markers for SNP array development is becoming more affordable. The SNP array is a very useful tool for high throughput genotyping and has a number of applications such as genome-wide association studies (GWAS). Since the...

Background/Objectives: The misincorporation of uracil into DNA leads to genomic instability. In a previous study, some of us identified four common single nucleotidepolymorphisms (SNPs) in uracil-processing genes (rs2029166 and rs7296239 in SMUG1, rs34259 in UNG and rs4775748 in DUT) that were asso...

A process to prepare high-density genotypic data for use in genomic prediction of genetic merit was developed. Marker genotypes from over 51,000 single nucleotidepolymorphisms (SNP) were generated for 3,139 Holstein bulls on the Illumina Bovine SNP50™ chip. The SNP were categorized by minor allele ...

Fertilization and development of the preimplantation embryo is under genetic control. The goal of the current study was to test 434 single nucleotidepolymorphisms (SNPs) for association with genetic variation in fertilization and early embryonic development. The approach was to produce embryos from...

Cotton genome complexity was investigated with a saturated molecular genetic map that combined several sets of microsatellites or simple sequence repeats (SSR) and the first major public set of single nucleotidepolymorphism (SNP) markers in cotton genomes (Gossypium spp.), and that was constructed ...

We report 34 new nuclear single-nucleotide-polymorphism (SNP) markers that have been developed from an expressed sequence tag library of Plasmopara viticola, the causal agent of grapevine downy mildew. This newly developed battery of markers will provide useful additional genetic tools for population genetic studies of this important agronomic species. PMID:21926208

A simple and low-cost colorimetric assay utilizing ferrofluidic nanoparticulate probes (FNPs) and a ligase for single-nucleotidepolymorphism genotyping is described. Excellent sensitivity and selectivity were accomplished through the engagement of the FNPs and a ligase chain reaction. PMID:23923128

We developed, identified and evaluated eight single nucleotidepolymorphism (SNP) and three sequence-tagged site (STS) markers in nuclear gene sequences of the wasp genus Nasonia (Hymenoptera). We studied variation of these markers in natural populations of the closely related and regionally sympatr...

The hyaluronan synthase 1 (HAS1) gene encodes a plasma membrane protein that synthesizes hyaluronan, an extracellular matrix molecule. Previously, in patients with Waldenstrom's macroglobulinemia (WM), we detected upregulation of HAS1 transcripts and identified aberrant splice variants of this gene. Aberrant splicing of HAS1 results from activation of cryptic splice sites. In turn, activation of cryptic donor and acceptor splice sites can be promoted by mutations occurring upstream of these sites and/or at the branch point of slicing. We measured the frequency of the HAS1 833A/G polymorphism (ie, single-nucleotidepolymorphism; SNP) in patients with WM and healthy donors. Additionally, HAS1 gene expression was evaluated in the same group of patients. Our observations so far suggest that HAS1 833A/G SNPs contribute to aberrant splicing of this gene; this idea is supported by the fact that 833A/G SNP is located on an exonic splicing enhancer motif. Based on the results obtained thus far, we speculate that individuals with HAS1 833G/G genotype are predisposed toward aberrant HAS1 splicing and expression of HAS1 variants, resulting in an enhanced risk of developing WM. Study of a larger group of patients and healthy donors is needed to confirm these speculations and to evaluate the prognostic significance of these findings. PMID:15794859

Genotyping of SNPs (single-nucleotidepolymorphisms) has challenged the development of several novel techniques. Most of these methods have been introduced to discriminate binary SNPs in diploid species. In the present study, the quantitative genotyping of SNPs in natural DNA pools of a polyploid organism via DNA microarrays was analysed. Three randomly selected SNP loci were genotyped in the tetraploid species potato (Solanum tuberosum). For each SNP, 24 oligomers were designed, 12 with forward and 12 with reverse orientation. They contained the polymorphic site at one of the positions 11, 14 and 17. Several steps of optimizations were performed, including the 'materials' used and the establishment of hybridization conditions. Glass surfaces were either epoxy- or aldehyde-modified, and allele-specific oligonucleotides contained either SH or NH2 groups. Hybridization stringency conditions were established by varying the concentration of formamide in the hybridization buffer. For SNP BA213c14t7/403, the quantitative discrimination between all four different naturally occurring genotypes could be demonstrated. PMID:15847606

Single nucleotidepolymorphism (SNP) in exon 1 and 3 of fibroblast growth factor (FGF5) gene was studied by DNA sequencing in Yingjing angora rabbit, Tianfu black rabbit and California rabbit. A frameshift mutation (TCT insert) at base position 217 (site A) of exon 1 and a T/C missense mutation at base position 59 (site B) of exon 3 were found in Yingjing angora rabbit with a high frequency; a T/C same-sense mutation at base position 3 (site C) of exon 3 was found with similar frequency in three rabbit breeds. Least square analysis showed that different genotypes had no significant association with wool yield in site A, and had high significant association with wool yield in site B (P<0.01) and significant association with wool yield in site C (P<0.05). It was concluded from the results that FGF5 gene could be the potential major gene affecting wool yield or link with the major gene, and polymorphic loci B and C may be used as molecular markers for im-proving wool yield in angora rabbits. PMID:18779133

A dual-probe real time PCR (qPCR) DNA-based analysis was devised for the identification of mandarin in orange juice. A single nucleotidepolymorphism at the trnL-trnF intergenic region of the chloroplast chromosome was confirmed in nine orange (Citrus sinensis) and thirteen commercial varieties of mandarin, including Citrus reticulata and Citrus unshiu species and a mandarin × tangelo hybrid. Two short minor-groove binding fluorescent probes targeting the polymorphic sequence were used in the dual-probe qPCR, which allowed the detection of both species in single-tube reactions. The similarity of PCR efficiencies allowed a simple estimation of the ratio mandarin/orange in the juice samples, which correlated to the measured difference of threshold cycle values for both probes. The limit of detection of the assay was 5% of mandarin in orange juice, both when the juice was freshly prepared (not from concentrate) or reconstituted from concentrate, which would allow the detection of fraudulently added mandarin juice. The possible use of the dual-probe system for quantitative measurements was also tested on fruit juice mixtures. qPCR data obtained from samples containing equal amounts of mandarin and orange juice revealed that the mandarin target copy number was approximately 2.6-fold higher than in orange juice. The use of a matrix-adapted control as calibrator to compensate the resulting C(T) bias allowed accurate quantitative measurements to be obtained. PMID:24128588

Large scale association studies have identified the single nucleotidepolymorphism rs3803662 associated with breast cancer risk. However, the sample size of most studies is too small. Here, we performed this meta-analysis to make the result more convincing. Relevant articles published up to 2016 were identified by searching the PubMed database. 13 studies, involving a total of 29405 participants, were included in the meta-analysis. Odds Ratios (ORs) with 95% confidence intervals (CIs) was calculated with random or fixed effects model. All data analyses were analyzed by Review Manger 5.3 software. In Caucasian subgroup: Dominant model (TT + CT vs CC): OR = 1.17 (1.06, 1.29), Recessive model (TT vs CT + CC): OR = 1.25 (1.13, 1.39) and Allele frequency (T vs C): OR = 1.15 (1.08, 1.22). The present meta-analysis suggests that rs3803662 polymorphism is significantly associated with breast cancer risk in Caucasian women, and we did not find the association in Asian women. PMID:27350156

Increasing evidence has demonstrated that lung fluid absorption disorders might be an important cause of neonatal respiratory distress syndrome (RDS) by influencing gas exchange or surfactant function. The SCNN1A gene, which encodes the α-ENaC, might predispose infants to RDS. To explore whether the single-nucleotidepolymorphisms (SNPs) of SCNN1A are associated with RDS, we conducted a case-control study to investigate the RDS-associated loci in Han Chinese infants. Seven target SNPs were selected from the SCNN1A gene and were genotyped using the improved multiplex ligase detection reaction (iMLDR). In the total sample, only rs4149570 was associated with NRDS; this association was further confirmed in logistic regression analysis after adjusting for birth weight, gestational age and sex. In the subgroup of infants whose gestational age was 37 weeks and older, in addition to rs4149570, rs7956915 also showed a significant association with RDS. Interestingly, these associations were only observed in term infants. No significant association was observed between the target SNPs and the risk of RDS in preterm infants. We report for the first time that the rs4149570 and rs7956915 polymorphisms of SCNN1A might play important roles in the susceptibility to RDS, particularly in term infants. PMID:26611714

MS is an autoimmune disease and interleukin 13 (IL-13) has been proposed to be an important neuroprotective mediator in MS. Because of plausible effect of single nucleotidepolymorphisms (SNPs) in expression level or biological activity of any cytokine, we sought to investigate association of IL-13 SNPs, C-1112T, A-1512C and G+2044A, with risk to MS. Sixty-eight RRMS patients and 110 healthy controls were involved in this study. After extraction of genomic DNA, frequency of genotypes and alleles were determined by PCR-RFLP and data were analyzed statistically. Results showed significant higher frequency of CC, CC, and AA genotypes and C, C, and A alleles of -1112CT, -1512AC and +2044GA SNPs respectively, in patients group. There was significant association between -1112C allele with onset age of MS. No significant association was seen between any of genotypes or alleles with expanded disability status scale (EDSS) of patients. Our findings showed significant association between three studied SNPs of IL-13 with susceptibility to MS in Iranian patients. More studies should be done on other IL-13 SNPs, and also polymorphisms of IL-13 receptor and other cytokines to determine the exact role of SNPs in protecting or predisposing of individuals for MS. PMID:25628961

Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotidepolymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity. PMID:23538839

Aldo-Keto Reductases (AKRs) are a superfamily of NAD(P)H linked oxidoreductases that are generally monomeric 34- 37 kDa proteins present in all phyla. The superfamily consists of 15 families, which contains 151 members (www.med.upenn.edu/akr). Thirteen human AKRs exist that use endogenous substrates (sugar and lipid aldehydes, prostaglandins, retinals and steroid hormones), and in many instances they regulate nuclear receptor signaling. Exogenous substrates include metabolites implicated in chemical carcinogenesis: NNK (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone), polycyclic aromatic hydrocarbon trans-dihydrodiols, and aflatoxin dialdehyde. Promoter analysis of the human genes identifies common elements involved in their regulation which include osmotic response elements, antioxidant response elements, xenobiotic response elements, AP-1 sites and steroid response elements. The human AKRs are highly polymorphic, and in some instances single nucleotidepolymorphisms (SNPs) of high penetrance exist. This suggests that there will be inter-individual variation in endogenous and xenobiotic metabolism which in turn affect susceptibility to nuclear receptor signaling and chemical carcinogenesis. PMID:17537398

Kawasaki disease (KD) is characterized by systemic vasculitis of unknown etiology. A study from Japan reported that G to A substitution of a single-nucleotidepolymorphism (SNP) located in the 5'-untranslated region of caspase 3 (CASP3) (rs72689236), which was associated with nuclear factor of activated T cell-mediated T-cell activation, is responsible for susceptibility to KD. This study was conducted to investigate whether the polymorphism of CASP3 is responsible for susceptibility and coronary artery lesion (CAL) formation in KD in the Taiwanese population. A total of 1092 subjects (341 KD patients and 751 controls) were investigated to identify an SNP of rs72689236 using Invader assays (Third Wave Technologies). Our data provided a borderline significant association between the genotypes and allele frequency of rs72689236 in control subjects and KD patients (P=0.0535 under the dominant model; P=0.0575 under the allelic model). The A allele of rs72689236 in KD patients and in patients with CAL and intravenous immunoglobulin resistance was seen in a higher frequency. Importantly, a significant association was obtained between rs72689236 and KD patients with aneurysm formation (P=0.009, under the recessive model). The A allele of rs72689236 is very likely to be a risk allele in the development of aneurysm in patients with KD. PMID:21160486

Despite the recognition that cortical thickness is heritable and correlates with intellectual ability in children and adolescents, the genes contributing to individual differences in these traits remain unknown. We conducted a large-scale association study in 1583 adolescents to identify genes affecting cortical thickness. Single-nucleotidepolymorphisms (SNPs; n=54 837) within genes whose expression changed between stages of growth and differentiation of a human neural stem cell line were selected for association analyses with average cortical thickness. We identified a variant, rs7171755, associating with thinner cortex in the left hemisphere (P=1.12 × 10−7), particularly in the frontal and temporal lobes. Localized effects of this SNP on cortical thickness differently affected verbal and nonverbal intellectual abilities. The rs7171755 polymorphism acted in cis to affect expression in the human brain of the synaptic cell adhesion glycoprotein-encoding gene NPTN. We also found that cortical thickness and NPTN expression were on average higher in the right hemisphere, suggesting that asymmetric NPTN expression may render the left hemisphere more sensitive to the effects of NPTN mutations, accounting for the lateralized effect of rs7171755 found in our study. Altogether, our findings support a potential role for regional synaptic dysfunctions in forms of intellectual deficits. PMID:24514566

We report the discovery and validation of a set of single nucleotidepolymorphisms (SNPs) between the reference Neurospora crassa strain Oak Ridge and the Mauriceville strain (FGSC 2555), of sufficient density to allow fine mapping of most loci. Sequencing of Mauriceville cDNAs and alignment to the completed genomic sequence of the Oak Ridge strain identified 19,087 putative SNPs. Of these, a subset was validated by cleaved amplified polymorphic sequence (CAPS), a simple and robust PCR-based assay that reliably distinguishes between SNP alleles. Experimental confirmation resulted in the development of 250 CAPS markers distributed evenly over the genome. To demonstrate the applicability of this map, we used bulked segregant analysis followed by interval mapping to locate the csp-1 mutation to a narrow region on LGI. Subsequently, we refined mapping resolution to 74 kbp by developing additional markers, resequenced the candidate gene, NCU02713.3, in the mutant background, and phenocopied the mutation by gene replacement in the WT strain. Together, these techniques demonstrate a generally applicable and straightforward approach for the isolation of novel genes from existing mutants. Data on both putative and validated SNPs are deposited in a customized public database at the Broad Institute, which encourages augmentation by community users. PMID:19015548

Follicle stimulating hormone β (FSHβ) of Japanese flounder ( Paralichthys olivaceus) plays a key role in the regulation of gonadal development. This study aimed to investigate molecular genetic characteristics of the FSHβ gene and elucidate the effects of single nucleotidepolymorphisms (SNPs) of FSHβ on reproductive traits in Japanese flounder. We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the FSHβ gene in 60 individuals. We identified only an SNP (T/C) in the coding region of exon3 of FSHβ. The SNP (T/C) did not lead to amino acid changes at the position 340 bp of FSHβ gene. Statistical analysis showed that the SNP was significantly associated with testosterone (T) level and gonadosomatic index (GSI) ( P < 0.05). Individuals with genotype TC of the SNP had significantly higher serum T levels and GSI ( P < 0.05) than that of genotype CC. Therefore, FSHβ gene could be a useful molecular marker in selection for prominent reproductive trait in Japanese Flounder.

A single nucleotidepolymorphism (SNP) associated with pungency was detected within an expressed sequence tag (EST) of 307 bp. This fragment was identified after expression analysis of the EST clone SB2-66 in placenta tissue of Capsicum fruits. Sequence alignments corresponding to this new fragment allowed us to identify an SNP between pungent and non-pungent accessions. Two methods were chosen for the development of the SNP marker linked to pungency: tetra-primer amplification refractory mutation system-PCR (tetra-primer ARMS-PCR) and cleaved amplified polymorphic sequence. Results showed that both methods were successful in distinguishing genotypes. Nevertheless, tetra-primer ARMS-PCR was chosen for SNP genotyping because it was more rapid, reliable and less cost-effective. The utility of this SNP marker for pungency was demonstrated by the ability to distinguish between 29 pungent and non-pungent cultivars of Capsicum annuum. In addition, the SNP was also associated with phenotypic pungent character in the tested genotypes of C. chinense, C. baccatum, C. frutescens, C. galapagoense, C. eximium, C. tovarii and C. cardenasi. This SNP marker is a faster, cheaper and more reproducible method for identifying pungent peppers than other techniques such as panel tasting, and allows rapid screening of the trait in early growth stages. PMID:17882396

The polymorphisms of tumour necrosis factor alpha-induced protein 3 (TNFAIP3) have been found to associate with several autoimmune diseases. This study aimed to explore the association of single nucleotidepolymorphisms (SNPs) of TNFAIP3 gene with systemic lupus erythematosus (SLE) in Han Chinese. Thirty-two SNPs were genotyped in 284 patients with SLE and 630 controls using the ligation detection reaction (LDR) method. The quality control steps and statistical analyses were performed using the plink 1.07 package and haploview software. We found that 13 SNPs in TNFAIP3 showed significant association with SLE (P 0.27). All 13 SNPs showed most significant association in the dominant model. In haplotype analysis, a long risk SNP haplotype (GCCCGTGTCATGG) showed most significant association (P = 1.00 × 10(-4) ). In conclusion, our data suggest that TNFAIP3 is a susceptible gene for SLE in the Han Chinese population. PMID:26846592

The OLR1 gene encodes the oxidized low-density lipoprotein receptor (LOX-1), which is responsible for the cellular uptake of oxidized LDL (Ox-LDL), foam cell formation in atheroma plaques and atherosclerotic plaque rupture. Alternative splicing (AS) of OLR1 exon 5 generates two protein isoforms with antagonistic functions in Ox-LDL uptake. Previous work identified six single nucleotidepolymorphisms (SNPs) in linkage disequilibrium that influence the inclusion levels of OLR1 exon 5 and correlate with the risk of cardiovascular disease. Here we use minigenes to recapitulate the effects of two allelic series (Low- and High-Risk) on OLR1 AS and identify one SNP in intron 4 (rs3736234) as the main contributor to the differences in exon 5 inclusion, while the other SNPs in the allelic series attenuate the drastic effects of this key SNP. Bioinformatic, proteomic, mutational and functional high-throughput analyses allowed us to define regulatory sequence motifs and identify SR protein family members (SRSF1, SRSF2) and HMGA1 as factors involved in the regulation of OLR1 AS. Our results suggest that antagonism between SRSF1 and SRSF2/HMGA1, and differential recognition of their regulatory motifs depending on the identity of the rs3736234 polymorphism, influence OLR1 exon 5 inclusion and the efficiency of Ox-LDL uptake, with potential implications for atherosclerosis and coronary disease. PMID:25904137

Large scale association studies have identified the single nucleotidepolymorphism rs3803662 associated with breast cancer risk. However, the sample size of most studies is too small. Here, we performed this meta-analysis to make the result more convincing. Relevant articles published up to 2016 were identified by searching the PubMed database. 13 studies, involving a total of 29405 participants, were included in the meta-analysis. Odds Ratios (ORs) with 95% confidence intervals (CIs) was calculated with random or fixed effects model. All data analyses were analyzed by Review Manger 5.3 software. In Caucasian subgroup: Dominant model (TT + CT vs CC): OR = 1.17 (1.06, 1.29), Recessive model (TT vs CT + CC): OR = 1.25 (1.13, 1.39) and Allele frequency (T vs C): OR = 1.15 (1.08, 1.22). The present meta-analysis suggests that rs3803662 polymorphism is significantly associated with breast cancer risk in Caucasian women, and we did not find the association in Asian women. PMID:27350156

Cannabis sativa is both an illegal drug and a legitimate crop. The differentiation of illegal drug Cannabis from non-drug forms of Cannabis is relevant in the context of the growth of fibre and seed oil varieties of Cannabis for commercial purposes. This differentiation is currently determined based on the levels of tetrahydrocannabinol (THC) in adult plants. DNA based methods have the potential to assay Cannabis material unsuitable for analysis using conventional means including seeds, pollen and severely degraded material. The purpose of this research was to develop a single nucleotidepolymorphism (SNP) assay for the differentiation of "drug" and "non-drug"Cannabis plants. An assay was developed based on four polymorphisms within a 399 bp fragment of the tetrahydrocannabinolic acid (THCA) synthase gene, utilising the snapshot multiplex kit. This SNP assay was tested on 94 Cannabis plants, which included 10 blind samples, and was able to differentiate between "drug" and "non-drug"Cannabis in all cases, while also differentiating between Cannabis and other species. Non-drug plants were found to be homozygous at the four sites assayed while drug Cannabis plants were either homozygous or heterozygous. PMID:21036496

Phylogenetic reconstruction using molecular data is often subject to homoplasy, leading to inaccurate conclusions about phylogenetic relationships among operational taxonomic units. Compared with other molecular markers, single-nucleotidepolymorphisms (SNPs) exhibit extremely low mutation rates, making them rare in recently emerged pathogens, but they are less prone to homoplasy and thus extremely valuable for phylogenetic analyses. Despite their phylogenetic potential, ascertainment bias occurs when SNP characters are discovered through biased taxonomic sampling; by using whole-genome comparisons of five diverse strains of Bacillus anthracis to facilitate SNP discovery, we show that only polymorphisms lying along the evolutionary pathway between reference strains will be observed. We illustrate this in theoretical and simulated data sets in which complex phylogenetic topologies are reduced to linear evolutionary models. Using a set of 990 SNP markers, we also show how divergent branches in our topologies collapse to single points but provide accurate information on internodal distances and points of origin for ancestral clades. These data allowed us to determine the ancestral root of B. anthracis, showing that it lies closer to a newly described “C” branch than to either of two previously described “A” or “B” branches. In addition, subclade rooting of the C branch revealed unequal evolutionary rates that seem to be correlated with ecological parameters and strain attributes. Our use of nonhomoplastic whole-genome SNP characters allows branch points and clade membership to be estimated with great precision, providing greater insight into epidemiological, ecological, and forensic questions. PMID:15347815

Despite the recognition that cortical thickness is heritable and correlates with intellectual ability in children and adolescents, the genes contributing to individual differences in these traits remain unknown. We conducted a large-scale association study in 1583 adolescents to identify genes affecting cortical thickness. Single-nucleotidepolymorphisms (SNPs; n=54,837) within genes whose expression changed between stages of growth and differentiation of a human neural stem cell line were selected for association analyses with average cortical thickness. We identified a variant, rs7171755, associating with thinner cortex in the left hemisphere (P=1.12 × 10(-)(7)), particularly in the frontal and temporal lobes. Localized effects of this SNP on cortical thickness differently affected verbal and nonverbal intellectual abilities. The rs7171755 polymorphism acted in cis to affect expression in the human brain of the synaptic cell adhesion glycoprotein-encoding gene NPTN. We also found that cortical thickness and NPTN expression were on average higher in the right hemisphere, suggesting that asymmetric NPTN expression may render the left hemisphere more sensitive to the effects of NPTN mutations, accounting for the lateralized effect of rs7171755 found in our study. Altogether, our findings support a potential role for regional synaptic dysfunctions in forms of intellectual deficits. PMID:24514566

Rice sucrose synthase 3 (RSUS3) is expressed predominantly in rice seed endosperm and is thought to play an important role in starch filling during the milky stage of rice seed ripening. Because the genetic diversity of this locus is not known yet, the full sequence of RSUS3 from 43 rice varieties was amplified to examine the distribution of DNA polymorphisms. A total of 254 sequence variants, including SNPs and insertion/deletions, were successfully identified in the 7733 bp sequence that comprises the promoter, exons and introns, and 3' downstream nontranscribed region (NTR). Eleven haplotypes were distinguished among the 43 rice varieties based on nucleotide variation in the 3 defined regions (5' NTR, transcript, and 3' NTR). The promoter region showed evidence of a base change on a cis-element that might influence the functional role of the motif in seed-specific expression. The genetic diversity of the RSUS3 gene sequences in the rice germplasm used in this study appears to be the result of nonrandom processes. Analysis of polymorphism sites indicated that at least 11 recombinations have occurred, primarily in the transcribed region. This finding provides insight into the development of a cladistic approach for establishing future genetic association studies of the RSUS3 locus. PMID:21914668

Plasmodium vivax, one of the five species of Plasmodium parasites that cause human malaria, is responsible for 25–40% of malaria cases worldwide. Malaria global elimination efforts will benefit from accurate and effective genotyping tools that will provide insight into the population genetics and diversity of this parasite. The recent sequencing of P. vivax isolates from South America, Africa, and Asia presents a new opportunity by uncovering thousands of novel single nucleotidepolymorphisms (SNPs). Genotyping a selection of these SNPs provides a robust, low-cost method of identifying parasite infections through their unique genetic signature or barcode. Based on our experience in generating a SNP barcode for P. falciparum using High Resolution Melting (HRM), we have developed a similar tool for P. vivax. We selected globally polymorphic SNPs from available P. vivax genome sequence data that were located in putatively selectively neutral sites (i.e., intergenic, intronic, or 4-fold degenerate coding). From these candidate SNPs we defined a barcode consisting of 42 SNPs. We analyzed the performance of the 42-SNP barcode on 87 P. vivax clinical samples from parasite populations in South America (Brazil, French Guiana), Africa (Ethiopia) and Asia (Sri Lanka). We found that the P. vivax barcode is robust, as it requires only a small quantity of DNA (limit of detection 0.3 ng/μl) to yield reproducible genotype calls, and detects polymorphic genotypes with high sensitivity. The markers are informative across all clinical samples evaluated (average minor allele frequency > 0.1). Population genetic and statistical analyses show the barcode captures high degrees of population diversity and differentiates geographically distinct populations. Our 42-SNP barcode provides a robust, informative, and standardized genetic marker set that accurately identifies a genomic signature for P. vivax infections. PMID:25781890

Plasmodium vivax, one of the five species of Plasmodium parasites that cause human malaria, is responsible for 25-40% of malaria cases worldwide. Malaria global elimination efforts will benefit from accurate and effective genotyping tools that will provide insight into the population genetics and diversity of this parasite. The recent sequencing of P. vivax isolates from South America, Africa, and Asia presents a new opportunity by uncovering thousands of novel single nucleotidepolymorphisms (SNPs). Genotyping a selection of these SNPs provides a robust, low-cost method of identifying parasite infections through their unique genetic signature or barcode. Based on our experience in generating a SNP barcode for P. falciparum using High Resolution Melting (HRM), we have developed a similar tool for P. vivax. We selected globally polymorphic SNPs from available P. vivax genome sequence data that were located in putatively selectively neutral sites (i.e., intergenic, intronic, or 4-fold degenerate coding). From these candidate SNPs we defined a barcode consisting of 42 SNPs. We analyzed the performance of the 42-SNP barcode on 87 P. vivax clinical samples from parasite populations in South America (Brazil, French Guiana), Africa (Ethiopia) and Asia (Sri Lanka). We found that the P. vivax barcode is robust, as it requires only a small quantity of DNA (limit of detection 0.3 ng/μl) to yield reproducible genotype calls, and detects polymorphic genotypes with high sensitivity. The markers are informative across all clinical samples evaluated (average minor allele frequency > 0.1). Population genetic and statistical analyses show the barcode captures high degrees of population diversity and differentiates geographically distinct populations. Our 42-SNP barcode provides a robust, informative, and standardized genetic marker set that accurately identifies a genomic signature for P. vivax infections. PMID:25781890

Human physical pigmentation is determined by the type and amount of melanin and the process of pigmentation production probably involves more than 100 genes. A failure to synthesize melanin results in oculocutaneous albinism (OCA). A recently identified form of OCA results from mutations in the Membrane Associated Transporter Protein (MATP) gene. The role of MATP in human pigmentation is not clear. We investigated the role of two nonpathogenic nonsynonymous single nucleotidepolymorphisms (SNPs) in the MATP gene to determine if they are associated with normal human skin, hair, and eye color variation. A total of 608 individuals from four different population groups (456 Caucasians, 31 Asians, 70 African-Americans, and 51 Australian Aborigines) were genotyped for c.814G>A (p.Glu272Lys) and c.1122C>G (p.Phe374Leu). Results indicate that the allele frequencies of both polymorphisms are significantly different between population groups. The two alleles, 374Leu and 272Lys, are significantly associated with dark hair, skin, and eye color in Caucasians. The odds ratios (ORs) of the LeuLeu genotype for black hair and olive skin are 25.63 and 28.65, respectively, and for the LysLys genotype are 43.23 and 8.27, respectively. The OR for eye color is lower at 3.48 for the LeuLeu and 6.57 for LysLys genotypes. This is the first report of this highly significant association of MATP polymorphisms with normal human pigmentation variation. PMID:15714523

The aim of the present study was to reveal the contribution of single nucleotidepolymorphisms of the interleukin‑6 (IL‑6) gene and the progression of venous thromboembolism (VTE). A case‑control study composed of 246 VTE patients, including 160 from the Han population (76 males and 84 females, mean age 57.41±13.25 years), 86 from the Uyghur population (41 males and 45 females, mean age 51.61±13.73 years) and 292 gender and ethnicity‑matched control participants, including 170 from the Han population (91 males and 79 females, mean age 55.82±11.83 years) and 122 from the Uyghur population (64 males and 58 females, mean age 53.52±13.64 years) were enrolled in the present study. The results demonstrated that the serum levels of IL‑6, C‑reactive protein (CRP), D‑dimer, fibrinogen, plasminogen activator inhibitor‑1 and leptin were significantly higher in the VTE group compared with the control group (P<0.05). The frequencies of the ‑572C/G promoter polymorphisms of the IL‑6 genotypes CC, CG and GG were identified to be 34, 48 and 18% in the Han population and 33, 47 and 20% in the Uyghur population, respectively. The allele frequency distributions of the C and G alleles were 58 and 42% in the Han population and 56 and 43% in the Uyghur population, respectively. Significant differences were identified in the ‑572C/G promoter polymorphisms between the VTE group and the control group (P<0.05). For the ‑597G/A polymorphism, all individuals carried the GG and GA genotype; AA genotypes were not detected. Logistic regression analysis was used to identify the risk factors for VTE, adjusting by confounding factors, the results of which demonstrated that the CC homozygote of the IL‑6 ‑572G/C, CRP, IL‑6 and high‑density lipoprotein‑cholesterol were independent risk factors of VTE (P<0.05). In conclusion, the ‑572G/C genotype of IL‑6 may be a genetic marker of VTE in the Han and Uyghur populations. PMID:25625484

Background The September 11, 2001 attacks on the World Trade Center and the Pentagon increased the concern about the potential for terrorist attacks on many vulnerable sectors of the US, including agriculture. The concentrated nature of crops, easily obtainable biological agents, and highly detrimental impacts make agroterrorism a potential threat. Although procedures for an effective criminal investigation and attribution following such an attack are available, important enhancements are still needed, one of which is the capability for fine discrimination among pathogen strains. The purpose of this study was to develop a molecular typing assay for use in a forensic investigation, using Wheat streak mosaic virus (WSMV) as a model plant virus. Method This genotyping technique utilizes single base primer extension to generate a genetic fingerprint. Fifteen single nucleotidepolymorphisms (SNPs) within the coat protein and helper component-protease genes were selected as the genetic markers for this assay. Assay optimization and sensitivity testing was conducted using synthetic targets. WSMV strains and field isolates were collected from regions around the world and used to evaluate the assay for discrimination. The assay specificity was tested against a panel of near-neighbors consisting of genetic and environmental near-neighbors. Result Each WSMV strain or field isolate tested produced a unique SNP fingerprint, with the exception of three isolates collected within the same geographic location that produced indistinguishable fingerprints. The results were consistent among replicates, demonstrating the reproducibility of the assay. No SNP fingerprints were generated from organisms included in the near-neighbor panel, suggesting the assay is specific for WSMV. Using synthetic targets, a complete profile could be generated from as low as 7.15 fmoles of cDNA. Conclusion The molecular typing method presented is one tool that could be incorporated into the forensic

Kelvin probe force microscopy (KPFM) is a robust toolkit for profiling the surface potential (SP) of biomolecular interactions between DNAs and/or proteins at the single molecule level. However, it has often suffered from background noise and low throughput due to instrumental or environmental constraints, which is regarded as limiting KPFM applications for detection of minute changes in the molecular structures such as single-nucleotidepolymorphism (SNP). Here, we show KPFM imaging of DNA-capped nanoparticles (DCNP) that enables SNP detection of the BRCA1 gene owing to sterically well-adjusted DNA-DNA interactions that take place within the confined spaces of DCNP. The average SP values of DCNP interacting with BRCA1 SNP were found to be lower than the DCNP reacting with normal (non-mutant) BRCA1 gene. We also demonstrate that SP characteristics of DCNP with different substrates (e.g., Au, Si, SiO2, and Fe) provide us with a chance to attenuate or augment the SP signal of DCNP without additional enhancement of instrumentation capabilities.Kelvin probe force microscopy (KPFM) is a robust toolkit for profiling the surface potential (SP) of biomolecular interactions between DNAs and/or proteins at the single molecule level. However, it has often suffered from background noise and low throughput due to instrumental or environmental constraints, which is regarded as limiting KPFM applications for detection of minute changes in the molecular structures such as single-nucleotidepolymorphism (SNP). Here, we show KPFM imaging of DNA-capped nanoparticles (DCNP) that enables SNP detection of the BRCA1 gene owing to sterically well-adjusted DNA-DNA interactions that take place within the confined spaces of DCNP. The average SP values of DCNP interacting with BRCA1 SNP were found to be lower than the DCNP reacting with normal (non-mutant) BRCA1 gene. We also demonstrate that SP characteristics of DCNP with different substrates (e.g., Au, Si, SiO2, and Fe) provide us with a

Background The common ancestor of salmonid fishes, including rainbow trout (Oncorhynchus mykiss), experienced a whole genome duplication between 20 and 100 million years ago, and many of the duplicated genes have been retained in the trout genome. This retention complicates efforts to detect allelic variation in salmonid fishes. Specifically, single nucleotidepolymorphism (SNP) detection is problematic because nucleotide variation can be found between the duplicate copies (paralogs) of a gene as well as between alleles. Results We present a method of differentiating between allelic and paralogous (gene copy) sequence variants, allowing identification of SNPs in organisms with multiple copies of a gene or set of genes. The basic strategy is to: 1) identify windows of unique cDNA sequences with homology to each other, 2) compare these unique cDNAs if they are not shared between individuals (i.e. the cDNA is homozygous in one individual and homozygous for another cDNA in the other individual), and 3) give a “SNP score” value between zero and one to each candidate sequence variant based on six criteria. Using this strategy we were able to detect about seven thousand potential SNPs from the transcriptomes of several clonal lines of rainbow trout. When directly compared to a pre-validated set of SNPs in polyploid wheat, we were also able to estimate the false-positive rate of this strategy as 0 to 28% depending on parameters used. Conclusions This strategy has an advantage over traditional techniques of SNP identification because another dimension of sequencing information is utilized. This method is especially well suited for identifying SNPs in polyploids, both outbred and inbred, but would tend to be conservative for diploid organisms. PMID:24237905

We develop color code-based pyrosequencing with di-base addition for analysis of single nucleotidepolymorphisms (SNPs). When a di-base is added into the polymerization, one or several two-color code(s) containing the type and the number of incorporated nucleotides will be produced. The code information obtained in a single run is useful to genotype SNPs as each allelic variant will give a specific pattern compared to the two other variants. Special care has to be taken while designing the di-base dispensation order. Here, we present a detailed protocol for establishing sequence-specific di-base addition to avoid nonsynchronous extension at the SNP sites. By using this technology, as few as 50 copies of DNA templates were accurately sequenced. Higher signals were produced and thus a relatively lower sample amount was required. Furthermore, the read length of per flow was increased, making simultaneous identification of multiple SNPs in a single sequencing run possible. Validation of the method was performed by using templates with two SNPs covering 37 bp and with three SNPs covering 58 bp as well as 82 bp. These SNPs were successfully genotyped by using only a sequencing primer in a single PCR/sequencing run. Our results demonstrated that this technology could be potentially developed into a powerful methodology to accurately determine SNPs so as to diagnose clinical settings. Graphical Abstract Conventional pyrosequencing adds one base (A, G, C, or T) at a time to determine the SNP site (left). Pyrosequencing with di-base addition adds di-base AG, AC, AT, CT, GC or GT at a time to determine the SNP site (right). Higher signals at SNP site will be produced due to the addition of di-bases. PMID:26935928

A nanoparticle-assembled photonic crystal (PC) array was used to detect single nucleotidepolymorphism (SNP). The assay platform with PC nanostructure enhanced the fluorescent signal from nanoparticle-hybridized DNA complexes due to phase matching of excitation and emission. Nanoparticles coupled with probe DNA were trapped into nanowells in an array by using an electrophoretic particle entrapment system. The PC/DNA assay platform was able to identify a 1 base pair (bp) difference in synthesized nucleotide sequences that mimicked the mutation seen in a feline model of human autosomal dominant polycystic kidney disease (PKD) with a sensitivity of 0.9 fg/mL (50 aM)-sensitivity, which corresponds to 30 oligos/array. The reliability of the PC/DNA assay platform to detect SNP in a real sample was demonstrated by using genomic DNA (gDNA) extracted from the urine and blood of two PKD− wild type and three PKD positive cats. The standard curves for PKD positive (PKD+) and negative (PKD−) DNA were created using two feline-urine samples. An additional three urine samples were analyzed in a similar fashion and showed satisfactory agreement with the standard curve, confirming the presence of the mutation in affected urine. The limit of detection (LOD) was 0.005 ng/mL which corresponds to 6 fg per array for gDNA in urine and blood. The PC system demonstrated the ability to detect a number of genome equivalents for the PKD SNP that was very similar to the results reported with real time polymerase chain reaction (PCR). The favorable comparison with quantitative PCR suggests that the PC technology may find application well beyond the detection of the PKD SNP, into areas where a simple, cheap and portable nucleic acid analysis is desirable. PMID:25580203

Feed efficiency and carcass characteristics are late-measured traits. The detection of molecular markers associated with them can help breeding programs to select animals early in life, and to predict breeding values with high accuracy. The objective of this study was to identify polymorphisms in the functional and positional candidate gene NEUROD1 (neurogenic differentiation 1), and investigate their associations with production traits in reference families of Nelore cattle. A total of 585 steers were used, from 34 sires chosen to represent the variability of this breed. By sequencing 14 animals with extreme residual feed intake (RFI) values, seven single nucleotidepolymorphisms (SNPs) in NEUROD1 were identified. The investigation of marker effects on the target traits RFI, backfat thickness (BFT), ribeye area (REA), average body weight (ABW), and metabolic body weight (MBW) was performed with a mixed model using the restricted maximum likelihood method. SNP1062, which changes cytosine for guanine, had no significant association with RFI or REA. However, we found an additive effect on ABW (P ≤ 0.05) and MBW (P ≤ 0.05), with an estimated allele substitution effect of -1.59 and -0.93 kg0.75, respectively. A dominant effect of this SNP for BFT was also found (P ≤ 0.010). Our results are the first that identify NEUROD1 as a candidate that affects BFT, ABW, and MBW. Once confirmed, the inclusion of this SNP in dense panels may improve the accuracy of genomic selection for these traits in Nelore beef cattle as this SNP is not currently represented on SNP chips. PMID:27420997

A commonly diagnosed cancer, prostate cancer (PrCa), is being regulated by the gene RNASEL previously known as PRCA1 codes for ribonuclease L which is an integral part of interferon regulated system that mediates antiviral and antiproliferative role of the interferons. Both somatic and germline mutations have been implicated to cause prostate cancer. With an array of available Single NucleotidePolymorphism data on dbSNP this study is designed to sort out functional SNPs in RNASEL by implementing different authentic computational tools such as SIFT, PolyPhen, SNPs&GO, Fathmm, ConSurf, UTRScan, PDBsum, Tm-Align, I-Mutant, and Project HOPE for functional and structural assessment, solvent accessibility, molecular dynamics, and energy minimization study. Among 794 RNASEL SNP entries 124 SNPs were found nonsynonymous from which SIFT predicted 13 nsSNPs as nontolerable whereas PolyPhen-2 predicted 28. SNPs found on the 3′ and 5′ UTR were also assessed. By analyzing six tools having different perspectives an aggregate result was produced where nine nsSNPs were found to be most likely to exert deleterious effect. 3D models of mutated proteins were generated to determine the functional and structural effect of the mutations on ribonuclease L. The initial findings were reinforced by the results from I-Mutant and Project HOPE as these tools predicted significant structural and functional instability of the mutated proteins. Expasy-ProSit tool defined the mutations to be situated in the functional domains of the protein. Considering previous analysis this study revealed a conclusive result deducing the available SNP data on the database by identifying the most damaging three nsSNP rs151296858 (G59S), rs145415894 (A276V), and rs35896902 (R592H). As such studies involving polymorphisms of RNASEL were none to be found, the results of the current study would certainly be helpful in future prospects concerning prostate cancer in males. PMID:26236721

Background Marbling defined by the amount and distribution of intramuscular fat is an economically important trait of beef cattle in Japan. We have recently reported that single nucleotidepolymorphisms (SNPs) in the endothelial differentiation, sphingolipid G-protein-coupled receptor, 1 (EDG1) gene were associated with marbling in Japanese Black beef cattle. As well as EDG1, the titin (TTN) gene, involved in myofibrillogenesis, has been previously shown to possess expression difference in musculus longissimus muscle between low-marbled and high-marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus TTN was considered as a positional functional candidate for the gene responsible for marbling. In this study, we explored SNP in TTN and analyzed association of the SNP with marbling. Findings A SNP in the promoter region of TTN, referred to as g.231054C>T, was the only difference detected between high- and low-marbled steer groups. The SNP was associated with marbling in 3 experiments using 101 sires (P = 0.004), 848 paternal half-sib progeny steers from 5 sires heterozygous for the g.231054C>T (P = 0.046), and 820 paternal half-sib progeny steers from 3 sires homozygous for C allele at the g.231054C>T (P = 0.051), in Japanese Black beef cattle. The effect of genotypes of the SNP on subcutaneous fat thickness was not statistically significant (P > 0.05). Conclusion These findings suggest that in addition to the EDG1 SNPs, the TTN SNP polymorphism is associated with marbling and may be useful for effective marker-assisted selection to increase the levels of marbling in Japanese Black beef cattle. Further replicate studies will be needed to confirm the allelic association observed here, and to expand the results to evaluate all possible genotypic combinations of alleles. PMID:19419586

Hepatocellular carcinoma (HCC) is etiologically linked with hepatitis B virus (HBV) and is the leading cause of death amongst 80% of HBV patients. Among HBV affected patients, genetic factors are also involved in modifying the risk factors of HCC. However, the genetic factors that regulate progression to HCC still remain to be determined. In this review, we discuss several single nucleotidepolymorphisms (SNPs) which were reportedly associated with increased or reduced risk of HCC occurrence in patients with chronic HBV infection such as cyclooxygenase (COX)-2 expression specifically at COX-2 -1195G/A in Chinese, Turkish and Egyptian populations, tumor necrosis factor α and the three most commonly studied SNPs: PAT-/+, Lys939Gln (A33512C, rs2228001) and Ala499Val (C21151T, rs2228000). In genome-wide association studies, strong associations have also been found at loci 1p36.22, 11q22.3, 6p21 (rs1419881, rs3997872, rs7453920 and rs7768538), 8p12 (rs2275959 and rs37821974) and 22q11.21. The genes implicated in these studies include HLA-DQB2, HLA-DQA1, TCF19, HLA-C, UBE2L3, LTL, FDX1, MICA, UBE4B and PG. The SNPs found to be associated with the above-mentioned genes still require validation in association studies in order to be considered good prognostic candidates for HCC. Screening of these polymorphisms is very beneficial in clinical experiments to stratify the higher or lower risk for HCC and may help in designing effective and efficient HCC surveillance programs for chronic HBV-infected patients if further genetic vulnerabilities are detected. PMID:27057306

Background Cattle that naturally do not grow horns are referred to as polled, a trait inherited in a dominant Mendelian fashion. Previous studies have localized the polled mutation (which is unknown) to the proximal end of bovine chromosome 1 in a region approximately 3 Mb in size. While a polled genetic test, Tru-Polled™, is commercially available from MetaMorphix Inc., Holsteins are not a validated breed for this test. Findings Approximately 160 kb were sequenced within the known polled region from 12 polled and 12 horned Holsteins. Analysis of the polymorphisms identified 13 novel single nucleotidepolymorphisms (SNPs) that are concordant with the horned/polled trait. Three of the 13 SNPs are located in gene coding or regulatory regions (e.g., the untranslated region, or UTR) where one is located in the 3'UTR of a gene and the other two are located in the 5'UTR and coding region (synonymous SNP) of another gene. The 3'UTR of genes have been shown to be targets of microRNAs regulating gene expression. In silico analysis indicates the 3'UTR SNP may disrupt a microRNA target site. Conclusion These 13 novel SNPs concordant with the horned/polled trait in Holsteins represent a test panel for the breed and this is the first report to the authors' knowledge of SNPs within gene coding or regulatory regions concordant with the horned/polled trait in cattle. These SNPs will require further testing for verification and further study to determine if the 3'UTR SNP may have a functional effect on the polled trait in Holsteins. PMID:19063733

Hepatocellular carcinoma (HCC) is etiologically linked with hepatitis B virus (HBV) and is the leading cause of death amongst 80% of HBV patients. Among HBV affected patients, genetic factors are also involved in modifying the risk factors of HCC. However, the genetic factors that regulate progression to HCC still remain to be determined. In this review, we discuss several single nucleotidepolymorphisms (SNPs) which were reportedly associated with increased or reduced risk of HCC occurrence in patients with chronic HBV infection such as cyclooxygenase (COX)-2 expression specifically at COX-2 -1195G/A in Chinese, Turkish and Egyptian populations, tumor necrosis factor α and the three most commonly studied SNPs: PAT-/+, Lys939Gln (A33512C, rs2228001) and Ala499Val (C21151T, rs2228000). In genome-wide association studies, strong associations have also been found at loci 1p36.22, 11q22.3, 6p21 (rs1419881, rs3997872, rs7453920 and rs7768538), 8p12 (rs2275959 and rs37821974) and 22q11.21. The genes implicated in these studies include HLA-DQB2, HLA-DQA1, TCF19, HLA-C, UBE2L3, LTL, FDX1, MICA, UBE4B and PG. The SNPs found to be associated with the above-mentioned genes still require validation in association studies in order to be considered good prognostic candidates for HCC. Screening of these polymorphisms is very beneficial in clinical experiments to stratify the higher or lower risk for HCC and may help in designing effective and efficient HCC surveillance programs for chronic HBV-infected patients if further genetic vulnerabilities are detected. PMID:27057306

Identifying features shaping the architecture of sequence variations is important for understanding genome evolution and mapping disease loci. In this study, high-resolution scanning of Alu-centered alignments of the human genome sequences has revealed a striking elevation of the frequency of single nucleotidepolymorphisms (SNP) in the body and tail of Alu sequences compared to flanking regions. This enhancement in SNP density is evident for all twenty-four chromosomes, and in both the Alu-body and Alu-tail, which together may be referred to as the Alu-SNPs. Reduced levels of Alu-SNPs in the sex chromosomes, especially in the non-recombining NRY region of the Y chromosome, are consistent with recombination events playing an important role in the enhancement. The Alu elements are unstable recombination-mutation hotspots in the human genome, and it is suggested that the Alu-SNPs represent a key manifestation of this instability. Variations in Alu-SNPs among the HapMap populations of northern and western European ancestry (CEU), Han Chinese from Beijing (CHB), Japanese from Tokyo (JPT), and Yoruba from Ibadan, Nigeria (YRI) indicate that the Alu-SNPs provide useful sequence markers, in addition to the Alu-insertion polymorphisms themselves, for the delineation of human genome evolution. That Alu-SNP levels are highest in the youngest Alu-Y, intermediate in the Alu-S of intermediate age, and lowest in the oldest Alu-J is consistent with the occurrence of not only genetic drift but also natural selection on the Alu-SNPs. Such evolutionary selection in turn suggests that Alu-SNPs might include potential sites of disease association, and therefore deserve detailed investigation. PMID:16380220

A commonly diagnosed cancer, prostate cancer (PrCa), is being regulated by the gene RNASEL previously known as PRCA1 codes for ribonuclease L which is an integral part of interferon regulated system that mediates antiviral and antiproliferative role of the interferons. Both somatic and germline mutations have been implicated to cause prostate cancer. With an array of available Single NucleotidePolymorphism data on dbSNP this study is designed to sort out functional SNPs in RNASEL by implementing different authentic computational tools such as SIFT, PolyPhen, SNPs&GO, Fathmm, ConSurf, UTRScan, PDBsum, Tm-Align, I-Mutant, and Project HOPE for functional and structural assessment, solvent accessibility, molecular dynamics, and energy minimization study. Among 794 RNASEL SNP entries 124 SNPs were found nonsynonymous from which SIFT predicted 13 nsSNPs as nontolerable whereas PolyPhen-2 predicted 28. SNPs found on the 3' and 5' UTR were also assessed. By analyzing six tools having different perspectives an aggregate result was produced where nine nsSNPs were found to be most likely to exert deleterious effect. 3D models of mutated proteins were generated to determine the functional and structural effect of the mutations on ribonuclease L. The initial findings were reinforced by the results from I-Mutant and Project HOPE as these tools predicted significant structural and functional instability of the mutated proteins. Expasy-ProSit tool defined the mutations to be situated in the functional domains of the protein. Considering previous analysis this study revealed a conclusive result deducing the available SNP data on the database by identifying the most damaging three nsSNP rs151296858 (G59S), rs145415894 (A276V), and rs35896902 (R592H). As such studies involving polymorphisms of RNASEL were none to be found, the results of the current study would certainly be helpful in future prospects concerning prostate cancer in males. PMID:26236721

Background The majority of the 2 million bovine single nucleotidepolymorphisms (SNPs) currently available in dbSNP have been identified in a single breed, Hereford cattle, during the bovine genome project. In an attempt to evaluate the variance of a second breed, we have produced a whole genome sequence at low coverage of a single Fleckvieh bull. Results We generated 24 gigabases of sequence, mainly using 36-bp paired-end reads, resulting in an average 7.4-fold sequence depth. This coverage was sufficient to identify 2.44 million SNPs, 82% of which were previously unknown, and 115,000 small indels. A comparison with the genotypes of the same animal, generated on a 50 k oligonucleotide chip, revealed a detection rate of 74% and 30% for homozygous and heterozygous SNPs, respectively. The false positive rate, as determined by comparison with genotypes determined for 196 randomly selected SNPs, was approximately 1.1%. We further determined the allele frequencies of the 196 SNPs in 48 Fleckvieh and 48 Braunvieh bulls. 95% of the SNPs were polymorphic with an average minor allele frequency of 24.5% and with 83% of the SNPs having a minor allele frequency larger than 5%. Conclusions This work provides the first single cattle genome by next-generation sequencing. The chosen approach - low to medium coverage re-sequencing - added more than 2 million novel SNPs to the currently publicly available SNP resource, providing a valuable resource for the construction of high density oligonucleotide arrays in the context of genome-wide association studies. PMID:19660108

The most common form of genetic variation, single nucleotidepolymorphisms or SNPs, can affect the way an individual responds to the environment and modify disease risk. Although most of the millions of SNPs have little or no effect on gene regulation and protein activity, there are many circumstances where base changes can have deleterious effects. Non-synonymous SNPs that result in amino acid changes in proteins have been studied because of their obvious impact on protein activity. It is well known that SNPs within regulatory regions of the genome can result in disregulation of gene transcription. However, the impact of SNPs located in putative regulatory regions, or rSNPs, is harder to predict for two primary reasons. First, the mechanistic roles of non-coding genomic sequence remain poorly defined. Second, experimental validation of the functional consequences of rSNPs is often slow and laborious. In this review, we summarize traditional and novel methodologies for candidate rSNPs selection, in particular in silico techniques that aid in candidate rSNP selection. Additionally we will discuss molecular biological techniques that assess the impact of rSNPs on binding of regulatory machinery, as well as functional consequences on transcription. Standard techniques such as EMSA and luciferase reporter constructs are still widely used to assess effects of rSNPs on binding and gene transcription; however, these protocols are often bottlenecks in the discovery process. Therefore, we highlight novel and developing high-throughput protocols that promise to aid in shortening the process of rSNP validation. Given the large amount of genomic information generated from a multitude of re-sequencing and genome-wide SNP array efforts, future focus should be to develop validation techniques that will allow greater understanding of the impact these polymorphisms have on human health and disease. PMID:18565787

Current literature gives evidence of an indisputable role adiponectin plays in adipose tissue metabolism and obesity-related diseases. Moreover, latest research efforts focus on linking genetic markers of this adipocytokine's gene (ADIPOQ) with cancer. Aim of this study was to determine the genotype distribution of single nucleotidepolymorphism +276G > T (rs1501299) in ADIPOQ and an attempt to identify the impact this polymorphism exerts on endometrial cancer risk in obese females. The test group comprised 90 women treated surgically for endometrial cancer between 2000 and 2012 in the Department of Surgical & Endoscopic Gynecology and Gynecologic Oncology, Polish Mothers' Memorial Hospital - Research Institute, Lodz, Poland. 90 individuals treated in the parallel period for uterine fibroids constituted the control group. Patients within both groups were stratified according to BMI into: lean, overweight and obese subjects. Statistical analysis was performed between two major groups and, furthermore, within the abovementioned subgroups. The analysis revealed that allele G of the investigated polymorphism in obese women with endometrial cancer is significantly more frequent, and allele T is significantly less frequent than in lean controls. However, no significant correlation was observed between the polymorphism and endometrial cancer in lean and overweight females. Single nucleotidepolymorphism +276G > T (rs1501299) in ADIPOQ may be considered to be a risk factor of endometrial cancer. Further research on SNP in EC is warranted to obtain more conclusive outcomes. PMID:26386690

Fusarium graminearum is one of the most important causes of wheat scab in different parts of the world. This fungus is able to produce widespread trichothecene mycotoxins such as nivalenol (NIV) and deoxynivalenol (DON) which are harmful for both human and animals. The Fg16 target is located in chromosome 1 of the F. graminearum genome coding for a hypothetical protein whose function is not yet known. The Fg16 gene is involved in lipid biosynthesis and leads to sexual development during colonization in wheat stalks. This gene is used to detect F. graminearum and determine the lineage of F. graminearum complex species. In the present study, polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and DNA sequencing methods were employed in screening for genetic variation in 172 F. graminearum s.s. isolates. The PCR reaction forced the amplification of 410-bp fragments of Fg16. Two single nucleotidepolymorphisms (T82C and A352T) and one amino acid exchange (C65S) with three patterns (TA/TA, CT/CT and TA/CT genotypes) were found in the Fg16 gene fragment. Two haplotypes, 1A and 1B, were identified within F. graminearum s.s. populations in northern and western regions of Iran. Two different secondary structures of protein were predicted for CT/CT and TA/CT genotypes of Fg16 gene. The average diversity levels detected were relatively high (He: 0.3238; Heu: 0.334; Ho: 0.2894; mean PIC: 0.514; mean Shannon's information index: 0.4132; mean number of alleles per locus: 1.473). On the basis of the obtained results, it was revealed that the Fg16 gene had a high degree of polymorphism that can be considered for future control programming strategies and thus the associations between the SSCP patterns with different traits of F. graminearum such as wheat colonization, perithecium formation on stalk tissues and lineage discrimination should be investigated. PMID:27222818

AIM: To investigate the role that single nucleotidepolymorphisms (SNPs) in the promoter of the tumour necrosis factor-alpha (TNF-α) gene play in the risk of inflammatory bowel diseases (IBDs) in a New Zealand population, in the context of international studies. METHODS: DNA samples from 388 patients with Crohn’s disease (CD), 405 ulcerative colitis (UC), 27 indeterminate colitis (IC) and 201 randomly selected controls, from Canterbury, New Zealand were screened for 3 common polymorphisms in the TNF-α receptor: -238 G→A, -308 G→A and -857C→T, using a TaqmanR assay. A meta-analysis was performed on the data obtained on these polymorphisms combined with that from other published studies. RESULTS: Individuals carrying the -308 G/A allele had a significantly (OR = 1.91, χ2 = 17.36, P < 0.0001) increased risk of pancolitis, and a 1.57-fold increased risk (OR = 1.57, χ2 = 4.34, P = 0.037) of requiring a bowel resection in UC. Carrying the -857 C/T variant decreased the risk of ileocolonic CD (OR = 0.56, χ2 = 4.32, P = 0.037), and the need for a bowel resection (OR = 0.59, χ2 = 4.85, P = 0.028). The risk of UC was reduced in individuals who were smokers at diagnosis, (OR = 0.48, χ2 = 4.86, P = 0.028). CONCLUSION: TNF-α is a key cytokine known to play a role in inflammatory response, and the locus for the gene is found in the IBD3 region on chromosome 6p21, known to be associated with an increased risk for IBD. The -308 G/A SNP in the TNF-α promoter is functional, and may account in part for the increased UC risk associated with the IBD3 genomic region. The -857 C/T SNP may decrease IBD risk in certain groups. Pharmaco- or nutrigenomic approaches may be desirable for individuals with such affected genotypes. PMID:18698679

Isoniazid (INH) is a central component of drug regimens used worldwide to treat tuberculosis. Previous studies have identified resistance-associated mutations in katG, inhA, kasA, ndh, and the oxyR-ahpC intergenic region. DNA microarray-based experiments have shown that INH induces several genes in Mycobacterium tuberculosis that encode proteins physiologically relevant to the drug's mode of action. To gain further insight into the molecular genetic basis of INH resistance, 20 genes implicated in INH resistance were sequenced for INH resistance-associated mutations. Thirty-eight INH-monoresistant clinical isolates and 86 INH-susceptible isolates of M. tuberculosis were obtained from the Texas Department of Health and the Houston Tuberculosis Initiative. Epidemiologic independence was established for all isolates by IS6110 restriction fragment length polymorphism analysis. Susceptible isolates were matched with resistant isolates by molecular genetic group and IS6110 profiles. Spoligotyping was done with isolates with five or fewer IS6110 copies. A major genetic group was established on the basis of the polymorphisms in katG codon 463 and gyrA codon 95. MICs were determined by the E-test. Semiquantitative catalase assays were performed with isolates with mutations in the katG gene. When the 20 genes were sequenced, it was found that 17 (44.7%) INH-resistant isolates had a single-locus, resistance-associated mutation in the katG, mabA, or Rv1772 gene. Seventeen (44.7%) INH-resistant isolates had resistance-associated mutations in two or more genes, and 76% of all INH-resistant isolates had a mutation in the katG gene. Mutations were also identified in the fadE24, Rv1592c, Rv1772, Rv0340, and iniBAC genes, recently shown by DNA-based microarray experiments to be upregulated in response to INH. In general, the MICs were higher for isolates with mutations in katG and the isolates had reduced catalase activities. The results show that a variety of single nucleotide

Fusarium graminearum is one of the most important causes of wheat scab in different parts of the world. This fungus is able to produce widespread trichothecene mycotoxins such as nivalenol (NIV) and deoxynivalenol (DON) which are harmful for both human and animals. The Fg16 target is located in chromosome 1 of the F. graminearum genome coding for a hypothetical protein whose function is not yet known. The Fg16 gene is involved in lipid biosynthesis and leads to sexual development during colonization in wheat stalks. This gene is used to detect F. graminearum and determine the lineage of F. graminearum complex species. In the present study, polymerase chain reaction–single strand conformational polymorphism (PCR–SSCP) and DNA sequencing methods were employed in screening for genetic variation in 172 F.graminearum s.s. isolates. The PCR reaction forced the amplification of 410-bp fragments of Fg16. Two single nucleotidepolymorphisms (T82C and A352T) and one amino acid exchange (C65S) with three patterns (TA/TA, CT/CT and TA/CT genotypes) were found in the Fg16 gene fragment. Two haplotypes, 1A and 1B, were identified within F. graminearum s.s. populations in northern and western regions of Iran. Two different secondary structures of protein were predicted for CT/CT and TA/CT genotypes of Fg16 gene. The average diversity levels detected were relatively high (He: 0.3238; Heu: 0.334; Ho: 0.2894; mean PIC: 0.514; mean Shannon's information index: 0.4132; mean number of alleles per locus: 1.473). On the basis of the obtained results, it was revealed that the Fg16 gene had a high degree of polymorphism that can be considered for future control programming strategies and thus the associations between the SSCP patterns with different traits of F. graminearum such as wheat colonization, perithecium formation on stalk tissues and lineage discrimination should be investigated. PMID:27222818

Genome wide association studies are central to the evolution of personalized medicine. However, the propensity for single nucleotidepolymorphisms (SNPs) to fall outside of genes means that understanding how these polymorphisms alter cellular function requires an expanded view of human genetics. Integrating the study of genome structure (chromosome conformation capture) into its function opens up new avenues of exploration. Changes in the epigenome associated with SNPs in gene deserts will allow us to define complex diseases in a much clearer manner, and usher in a new era of disease pathway exploration. PMID:24600475

The current study reports an assay approach that can detect single-nucleotidepolymorphisms (SNPs) and identify the position of the point mutation through a single-strand-specific nuclease reaction and a gold nanoparticle assembly. The assay can be implemented via three steps: a single-strand-specific nuclease reaction that allows the enzyme to truncate the mutant DNA; a purification step that uses capture probe-gold nanoparticles and centrifugation; and a hybridization reaction that induces detector probe-gold nanoparticles, capture probe-gold nanoparticles, and the target DNA to form large DNA-linked three-dimensional aggregates of gold nanoparticles. At high temperature (63 degrees C in the current case), the purple color of the perfect match solution would not change to red, whereas a mismatched solution becomes red as the assembled gold nanoparticles separate. Using melting analysis, the position of the point mutation could be identified. This assay provides a convenient colorimetric detection that enables point mutation identification without the need for expensive mass spectrometry. To our knowledge, this is the first report concerning SNP detection based on a single-strand-specific nuclease reaction and a gold nanoparticle assembly. PMID:18211817

Wolfram syndrome (WS) is a rare, progressive, neurodegenerative disorder that has an autosomal recessive pattern of inheritance. The gene for WS, wolfram syndrome 1 gene (WFS1), is located on human chromosome 4p16.1 and encodes a transmembrane protein. To date, approximately 230 mutations in WFS1 have been confirmed, in which nonsynonymous single nucleotidepolymorphisms (nsSNPs) are the most common forms of genetic variation. Nonetheless, there is poor knowledge on the relationship between SNP genotype and phenotype in other nsSNPs of the WFS1 gene. Here, we analysed 395 nsSNPs associated with the WFS1 gene using different computational methods and identified 20 nsSNPs to be potentially pathogenic. Furthermore, to identify the amino acid distributions and significances of pathogenic nsSNPs in the protein of WFS1, its transmembrane domain was constructed by the TMHMM server, which suggested that mutations outside of the TMhelix could have more effects on protein function. The predicted pathogenic mutations for the nsSNPs of the WFS1 gene provide an excellent guide for screening pathogenic mutations. PMID:26435059

The thyrocytes are exposed to high levels of oxidative stress which could induce DNA damages. Base excision repair (BER) is one of the principal mechanisms of defense against oxidative DNA damage, however recent evidences suggest that also nucleotide excision repair (NER) could be involved. The aim of present work was to identify novel differentiated thyroid cancer (DTC) risk variants in BER and NER genes. For this purpose, the most strongly associated SNPs within NER and BER genes found in our previous GWAS on DTC were selected and replicated in an independent series of samples for a new case-control study. Although a positive signal was detected at the nominal level of 0.05 for rs7689099 (encoding for an aminoacid change proline to arginine at codon 117 within NEIL3), none of the considered SNPs (i.e. rs7990340 and rs690860 within RFC3, rs3744767 and rs1131636 within RPA1, rs16962916 and rs3136166 in ERCC4, and rs17739370 and rs7689099 in NEIL3) was associated with the risk of DTC when the correction of multiple testing was applied. In conclusion, a role of NER and BER pathways was evoked in the susceptibility to DTC. However, this seemed to be limited to few polymorphic genes and the overall effect size appeared weak. PMID:27062014

Our previous works showed that single nucleotidepolymorphisms (SNPs) in genes with regulatory function upon inflammatory response and cholesterol metabolism were associated with Alzheimer's disease (AD) risk. The list comprises SNPs located on the promoters of alpha 1 antichymotrypsin (rs1884082), hydroxy methyl glutaryl coenzime A reductase (rs376140), tumor necrosis factor alpha (rs1800629), and interleukin 10 (rs1800869). Here we investigated the effect of these SNPs on the binding for transcription factors. We computationally detected putative binding sites for transcription factors located in the SNP regions. To this aim, the TESS program for scanning the promoter sequences against the binding-site models available at TRANSFACT and JASPAR databases was adopted. All the analyzed SNPs appeared to affect the binding of myeloid zinc finger protein 1 (MZF-1) to the promoter sequence of the above reported genes. Therefore 16 SNPs in MZF-1 gene were tested in 120 AD cases and 88 controls to asses a possible association between MZF-1 and AD. 14 SNPs showed no variability in AD and control populations, while two SNPs rs4756 and rs2228162 showed the three genotypes. Genotype distributions and allele frequencies of these two SNPs were comparable between AD and controls. On the other hand, the haplotype distribution of rs4756 and rs2228162 was different between AD and controls; being the AG haplotype associated with a decreased AD risk. In conclusion, selected SNPs in MZF-1 gene exert a minor effect on AD risk. PMID:23241556

We investigated the single nucleotidepolymorphism (SNP) density across the human genome and in different genic categories using two SNP databases: Celera's CgsSNP, which includes SNPs identified by comparing genomic sequences, and Celera's RefSNP, which includes SNPs from a variety of sources and is biased toward disease-associated genes. Based on CgsSNP, the average numbers of SNPs per 10 kb was 8.33, 8.44, and 8.09 in the human genome, in intergenic regions, and in genic regions, respectively. In genic regions, the SNP density in intronic, exonic and adjoining untranslated regions was 8.21, 5.28, and 7.51 SNPs per 10 kb, respectively. The pattern of SNP density based on RefSNP was different from that based on CgsSNP, emphasizing its utility for genotype-phenotype association studies but not for most population genetic studies. The number of SNPs per chromosome was correlated with chromosome length, but the density of SNPs estimated by CgsSNP was not significantly correlated with the GC content of the chromosome. Based on CgsSNP, the ratio of nonsense to missense mutations (0.027), the ratio of missense to silent mutations (1.15), and the ratio of non-synonymous to synonymous mutations (1.18) was less than half of that expected in a human protein coding sequence under the neutral mutation theory, reflecting a role for natural selection, especially purifying selection. PMID:12909357

Schizophrenia is a severe and complex mental disorder with high heritability. There is evidence that mutations in the gene of Nmethyl-d-aspartate-type glutamate receptors (NMDAR) are associated with schizophrenia. GRIN2B encodes a subunit of NMDARs, and has been identified as a candidate gene for many psychiatric disorders, especially schizophrenia. In this study, we investigated whether single nucleotidepolymorphisms (SNPs) in GRIN2B were associated with schizophrenia. Four SNPs (rs890, rs1806191, rs219872, rs172677) were genotyped in 752 schizophrenic patients and 846 healthy controls of the Chinese Han population. Our results indicate differences in allele and genotype frequencies of rs890 between case and control. These results were assessed by adapting different genetic models (codominant, dominant, recessive, overdominant, log-additive models). After controlling for confounding factors including sex and age, rs890 remained associated with schizophrenia. In addition, rs890 and rs1806191 were found to form a haplotype associated with schizophrenia. In summary, our results indicate that the GRIN2B SNP rs890 might be associated with schizophrenia in the Chinese Han population. PMID:27453061

Circadian rhythm disruptions are prominently associated with bipolar disorder (BD). Circadian rhythms are regulated by the molecular clock, a family of proteins that function together in a transcriptional-translational feedback loop. The CLOCK protein is a key transcription factor of this feedback loop, and previous studies have found that manipulations of the Clock gene are sufficient to produce manic-like behavior in mice (1). The CLOCK 3111T/C single-nucleotidepolymorphism (SNP; rs1801260) is a genetic variation of the human CLOCK gene that is significantly associated with increased frequency of manic episodes in BD patients (2). The 3111T/C SNP is located in the 3'-untranslated region of the CLOCK gene. In this study, we sought to examine the functional implications of the human CLOCK 3111T/C SNP by transfecting a mammalian cell line (mouse embryonic fibroblasts isolated from Clock(-/-) knockout mice) with pcDNA plasmids containing the human CLOCK gene with either the T or C SNP at position 3111. We then measured circadian gene expression over a 24-h time period. We found that the CLOCK3111C SNP resulted in higher mRNA levels than the CLOCK 3111T SNP. Furthermore, we found that Per2, a transcriptional target of CLOCK, was also more highly expressed with CLOCK 3111C expression, indicating that the 3'-UTR SNP affects the expression, function, and stability of CLOCK mRNA. PMID:27148095

Non-canonical guanine quadruplex structures are not only predominant but also conserved among bacterial and mammalian promoters. Moreover recent findings directly implicate quadruplex structures in transcription. These argue for an intrinsic role of the structural motif and thereby posit that single nucleotidepolymorphisms (SNP) that compromise the quadruplex architecture could influence function. To test this, we analysed SNPs within quadruplex motifs (Quad-SNP) and gene expression in 270 individuals across four populations (HapMap) representing more than 14 500 genotypes. Findings reveal significant association between quadruplex-SNPs and expression of the corresponding gene in individuals (P

A continuous-flow microchip with a temperature gradient in microchannels was utilized to demonstrate spatial melting analysis on microbeads for clinical Single NucleotidePolymorphisms (SNPs) genotyping on animal genomic DNA. The chip had embedded heaters and thermometers, which created a rapid and yet stable temperature gradient between 60 °C and 85 °C in a short distance as the detection region. The microbeads, which served as mobile supports carrying the target DNA and fluorescent dye, were transported across the temperature gradient. As the surrounding temperature increased, the fluorescence signals of the microbeads decayed with this relationship being acquired as the melting curve. Fast DNA denaturation, as a result of the improved heat transfer and thermal stability due to scaling, was also confirmed. Further, each individual microbead could potentially bear different sequences and pass through the detection region, one by one, for a series of melting analysis, with multiplex, high-throughput capability being possible. A prototype was tested with target DNA samples in different genotypes (i.e., wild and mutant types) with a SNP location from Landrace sows. The melting temperatures were obtained and compared to the ones using a traditional tube-based approach. The results showed similar levels of SNP discrimination, validating our proposed technique for scanning homozygotes and heterozygotes to distinguish single base changes for disease research, drug development, medical diagnostics, agriculture, and animal production. PMID:25553186

Eurycoma longifolia Jack. is a treelet that grows in the forests of Southeast Asia and is widely used throughout the region because of its reported medicinal properties. Widespread harvesting of wild-grown trees has led to rapid thinning of natural populations, causing a potential decrease in genetic diversity among E. longifolia. Suitable genetic markers would be very useful for propagation and breeding programs to support conservation of this species, although no such markers currently exist. To meet this need, we have applied a genome complexity reduction strategy to identify a series of single nucleotidepolymorphisms (SNPs) within the genomes of several E. longifolia accessions. We have found that the occurrence of these SNPs reflects the geographic origins of individual plants and can distinguish different natural populations. This work demonstrates the rapid development of molecular genetic markers in species for which little or no genomic sequence information is available. The SNP markers that we have developed in this study will also be useful for identifying genetic fingerprints that correlate with other properties of E. longifolia, such as high regenerability or the appearance of bioactive metabolites. PMID:12644679

Transcriptional profiling not only provides insights into patterns of gene expression, but also generates sequences that can be mined for molecular markers, which in turn can be used for population genetic studies. As part of a large-scale effort to better understand how commercially important European shellfish species may respond to ocean acidification, we therefore mined the transcriptomes of four species (the Pacific oyster Crassostrea gigas, the blue mussel Mytilus edulis, the great scallop Pecten maximus and the blunt gaper Mya truncata) for single nucleotidepolymorphisms (SNPs). Illumina data for C. gigas, M. edulis and P. maximus and 454 data for M. truncata were interrogated using GATK and SWAP454 respectively to identify between 8267 and 47,159 high quality SNPs per species (total=121,053 SNPs residing within 34,716 different contigs). We then annotated the transcripts containing SNPs to reveal homology to diverse genes. Finally, as oceanic pH affects the ability of organisms to incorporate calcium carbonate, we honed in on genes implicated in the biomineralization process to identify a total of 1899 SNPs in 157 genes. These provide good candidates for biomarkers with which to study patterns of selection in natural or experimental populations. PMID:26806806

Kelvin probe force microscopy (KPFM) is a robust toolkit for profiling the surface potential (SP) of biomolecular interactions between DNAs and/or proteins at the single molecule level. However, it has often suffered from background noise and low throughput due to instrumental or environmental constraints, which is regarded as limiting KPFM applications for detection of minute changes in the molecular structures such as single-nucleotidepolymorphism (SNP). Here, we show KPFM imaging of DNA-capped nanoparticles (DCNP) that enables SNP detection of the BRCA1 gene owing to sterically well-adjusted DNA-DNA interactions that take place within the confined spaces of DCNP. The average SP values of DCNP interacting with BRCA1 SNP were found to be lower than the DCNP reacting with normal (non-mutant) BRCA1 gene. We also demonstrate that SP characteristics of DCNP with different substrates (e.g., Au, Si, SiO2, and Fe) provide us with a chance to attenuate or augment the SP signal of DCNP without additional enhancement of instrumentation capabilities. PMID:27127876

We develop a computational framework for addressing pedigree inference problems using small numbers (80-400) of single nucleotidepolymorphisms (SNPs). Our approach relaxes the assumptions, which are commonly made, that sampling is complete with respect to the pedigree and that there is no genotyping error. It relies on representing the inferred pedigree as a factor graph and invoking the Sum-Product algorithm to compute and store quantities that allow the joint probability of the data to be rapidly computed under a large class of rearrangements of the pedigree structure. This allows efficient MCMC sampling over the space of pedigrees, and, hence, Bayesian inference of pedigree structure. In this paper we restrict ourselves to inference of pedigrees without loops using SNPs assumed to be unlinked. We present the methodology in general for multigenerational inference, and we illustrate the method by applying it to the inference of full sibling groups in a large sample (n=1157) of Chinook salmon typed at 95 SNPs. The results show that our method provides a better point estimate and estimate of uncertainty than the currently best-available maximum-likelihood sibling reconstruction method. Extensions of this work to more complex scenarios are briefly discussed. PMID:26450523

In the future, analysis of single nucleotidepolymorphisms (SNPs) should become a powerful tool for many genetic applications in areas such as association studies, pharmacogenetics and traceability in the agro-alimentary sector. A number of technologies have been developed for high-throughput genotyping of SNPs. Here we present the simplified GOOD assay for SNP genotyping by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI). The simplified GOOD assay is a single-tube, purification-free, three-step procedure consisting of PCR, primer extension and phosphodiesterase II digestion followed by mass spectrometric analysis. Due to the application of charge-tag technology, no sample purification is required prior to the otherwise very impurity-sensitive MALDI analysis. The use of methylphosphonate containing primers and ddNTPs or alpha-S-ddNTPs together with a novel DNA polymerase derived from Thermotoga maritima for primer extension allow the fluent preparation of negatively charge-tagged, allele-specific products. A key feature of this polymerase is its preference for ddNTPs and alpha-S-ddNTPs over dNTPs. The simplified GOOD assay was run with automatic liquid handling at the lowest manageable volumes, automatic data acquisition and interpretation. We applied this novel procedure to genotyping SNPs of candidate genes for hypertension and cardiovascular disease. PMID:11861927

Genetic variation is associated with diseases. As a type of genetic variation occurring with certain regularity and frequency, the single nucleotidepolymorphism (SNP) is attracting more and more attention because of its great value for research and real-life application. Mitochondrial antiviral signalling protein (MAVS) acts as a common adaptor molecule for retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), which can recognize foreign RNA, including viral RNA, leading to the induction of type I interferons (IFNs). Therefore, MAVS is thought to be a crucial molecule in antiviral innate immunity. We speculated that genetic variation of MAVS may result in susceptibility to infectious diseases. To assess the risk of viral infection based on MAVS variation, we tested the effects of twelve non-synonymous MAVS coding-region SNPs from the National Center for Biotechnology Information (NCBI) database that result in amino acid substitutions. We found that five of these SNPs exhibited functional alterations. Additionally, four resulted in an inhibitory immune response, and one had the opposite effect. In total, 1,032 human genomic samples obtained from a mass examination were genotyped at these five SNPs. However, no homozygous or heterozygous variation was detected. We hypothesized that these five SNPs are not present in the Japanese population and that such MAVS variations may result in serious immune diseases. PMID:26954674

A number of single nucleotidepolymorphisms (SNPs) are considered to be candidate susceptibility or resistance genetic factors for multifactorial disease. Genome-wide searches for disease susceptibility regions followed by high-resolution mapping of primary genes require cost-effective and highly reliable technology. To accomplish successful and low-cost typing for candidate SNPs, new technologies must be developed. We previously reported a multiplex SNP typing method, designated the DigiTag assay, that has the potential to analyze nearly any SNP with high accuracy and reproducibility. However, the DigiTag assay requires multiple washing steps in manipulation and uses genotyping probes modified with biotin for each target SNP. Here we describe the next version of the assay, DigiTag2, which works with simple protocols and uses unmodified genotyping probes. We investigated the feasibility of the DigiTag2 assay by genotyping 96 target SNPs spanning a 610-kb region of human chromosome 5. The DigiTag2 assay is suitable for genotyping an intermediate number of SNPs (tens to hundreds of sites) with a high conversion rate (>90%), high accuracy, and low cost. PMID:17359929

Tenascin-X (TNX) is an extra-cellular matrix glycoprotein associated with collagen fibril deposition. Recent reports have linked truncated TNX mutations (TNXB) to generalized joint hypermobility and most importantly recurrent joint dislocation. In the present study, we investigated whether there is an association between joint dislocation recurrence rate and the frequency of TNXB single-nucleotidepolymorphisms (SNPs). Seventy-eight patients treated for post-traumatic shoulder instability and 82 healthy controls were genotyped for selected TNXB SNP using TaqMan® Genotyping Assays. At a mean follow-up of 24 months recurrence rate and clinical outcomes were evaluated using the Constant and Murley, Rowe, and DASH scores. The association between genotypes and joint dislocation was tested using the dominant, recessive and additive models, and the model-free approach. Genotype distribution of the examined SNPs did not significantly deviate from the Hardy-Weinberg equilibrium (HWE) neither in patients nor in the controls. Moreover, there was no significant difference in genotype and allele distribution between patients and controls. Finally, no difference in genotype frequency was detected between patients who experienced a re-dislocation after the initial surgery and patients who did not sustain a re-dislocation. The SNPs investigated in this study have no clinically relevant influence on TNXB gene expression and/or TNX function. Therefore, these SNPs could not be used for predicting individual risk of recurrent shoulder dislocation. PMID:22991340

In clinical diagnostics, single nucleotidepolymorphism (SNP)-based microarray analysis enables the detection of copy number variations (CNVs), as well as copy number neutral regions, that are absent of heterozygosity throughout the genome. The aim of the present study was to evaluate the effectiveness and sensitivity of SNP-based microarray analysis in the diagnosis of hydatidiform mole (HM). By using whole-genome SNP microarray analysis, villous genotypes were detected, and the ploidy of villous tissue was determined to identify HMs. A total of 66 villous tissues and two twin tissues were assessed in the present study. Among these samples, 11 were triploid, one was tetraploid, 23 were abnormal aneuploidy, three were complete genome homozygosity, and the remaining ones were normal ploidy. The most noteworthy finding of the present study was the identification of six partial HMs and three complete HMs from those samples that were not identified as being HMs on the basis of the initial diagnosis of experienced obstetricians. This study has demonstrated that the application of an SNP-based microarray analysis was able to increase the sensitivity of diagnosis for HMs with partial and complete HMs, which makes the identification of these diseases at an early gestational age possible. PMID:27151252

Genome scans in the pig have identified a region on chromosome 2 (SSC2) associated with tenderness. Calpastatin is a likely positional candidate gene in this region because of its inhibitory role in the calpain system that is involved in postmortem tenderization. Novel single nucleotidepolymorphisms (SNP) in calpastatin were identified and used to genotype a population (n = 1042) of Duroc-Landrace-Yorkshire swine for association with longissimus lumborum slice shear force (SSF) measured at days 7 and 14 postmortem. Three genetic markers residing in the calpastatin gene were significantly associated with SSF (P < 0.0005). Haplotypes constructed from markers in the calpastatin gene were significantly associated with SSF (F-ratio = 3.93; P-value = 0.002). The levels of normalized mRNA expression of calpastatin in the longissimus lumborum of 162 animals also were evaluated by real-time RT-PCR and were associated with the genotype of the most significant marker for SSF (P < 0.02). This evidence suggests that the causative variation alters expression of calpastatin, thus affecting tenderness. In summary, these data provide evidence of several significant, publicly available SNP markers associated with SSF that may be useful to the swine industry for marker assisted selection of animals that have more tender meat. PMID:19422367

Studies of the oceanic and near-shore distributions of Pacific salmon, whose migrations typically span thousands of kilometres, have become increasingly valuable in the presence of climate change, increasing hatchery production and potentially high rates of bycatch in offshore fisheries. Genetics data offer considerable insights into both the migratory routes as well as the evolutionary histories of the species. However, these types of studies require extensive data sets from spawning populations originating from across the species' range. Single nucleotidepolymorphisms (SNPs) have been particularly amenable for multinational applications because they are easily shared, require little interlaboratory standardization and can be assayed through increasingly efficient technologies. Here, we discuss the development of a data set for 114 populations of chum salmon through a collaboration among North American and Asian researchers, termed PacSNP. PacSNP is focused on developing the database and applying it to problems of international interest. A data set spanning the entire range of species provides a unique opportunity to examine patterns of variability, and we review issues associated with SNP development. We found evidence of ascertainment bias within the data set, variable linkage relationships between SNPs associated with ancestral groupings and outlier loci with alleles associated with latitude. PMID:21429175

In this work, we report the application of streptavidin-coated quantum dot (strAV-QD) in molecular beacon (MB) microarray assays by using the strAV-QD to label the immobilized MB, avoiding target labeling and meanwhile obviating the use of amplification. The MBs are stem-loop structured oligodeoxynucleotides, modified with a thiol and a biotin at two terminals of the stem. With the strAV-QD labeling an "opened" MB rather than a "closed" MB via streptavidin-biotin reaction, a sensitive and specific detection of label-free target DNA sequence is demonstrated by the MB microarray, with a signal-to-background ratio of 8. The immobilized MBs can be perfectly regenerated, allowing the reuse of the microarray. The MB microarray also is able to detect single nucleotidepolymorphisms, exhibiting genotype-dependent fluorescence signals. It is demonstrated that the MB microarray can perform as a 4-to-2 encoder, compressing the genotype information into two outputs. PMID:26397421

The regenerative abilities and the immunosuppressive properties of mesenchymal stromal cells (MSCs) make them potentially the ideal cellular product of choice for treatment of autoimmune and other immune mediated disorders. Although the usefulness of MSCs for therapeutic applications is in early phases, their potential clinical use remains of great interest. Current clinical evidence of use of MSCs from both autologous and allogeneic sources to treat autoimmune disorders confers conflicting clinical benefit outcomes. These varied results may possibly be due to MSC use across wide range of autoimmune disorders with clinical heterogeneity or due to variability of the cellular product. In the light of recent genome wide association studies (GWAS), linking predisposition of autoimmune diseases to single nucleotidepolymorphisms (SNPs) in the susceptible genetic loci, the clinical relevance of MSCs possessing SNPs in the critical effector molecules of immunosuppression is largely undiscussed. It is of further interest in the allogeneic setting, where SNPs in the target pathway of MSC's intervention may also modulate clinical outcome. In the present review, we have discussed the known critical SNPs predisposing to disease susceptibility in various autoimmune diseases and their significance in the immunomodulatory properties of MSCs. PMID:24350294

Here we report a large, extensively characterized set of single-nucleotidepolymorphisms (SNPs) covering the human genome. We determined the allele frequencies of 55,018 SNPs in African Americans, Asians (Japanese–Chinese), and European Americans as part of The SNP Consortium’s Allele Frequency Project. A subset of 8333 SNPs was also characterized in Koreans. Because these SNPs were ascertained in the same way, the data set is particularly useful for modeling. Our results document that much genetic variation is shared among populations. For autosomes, some 44% of these SNPs have a minor allele frequency ≥10% in each population, and the average allele frequency differences between populations with different continental origins are less than 19%. However, the several percentage point allele frequency differences among the closely related Korean, Japanese, and Chinese populations suggest caution in using mixtures of well-established populations for case–control genetic studies of complex traits. We estimate that ~7% of these SNPs are private SNPs with minor allele frequencies <1%. A useful set of characterized SNPs with large allele frequency differences between populations (>60%) can be used for admixture studies. High-density maps of high-quality, characterized SNPs produced by this project are freely available. PMID:15961272

Understanding the complexities of DNA has been a hallmark of science for over a half century, and one of the important topics in DNA research is recognizing the occurrence of mutations in the base-stack. In this article, we present a study of SNPs by direct-contact electrical measurements to a single DNA duplex. We have used short, 11- and 12-bp dsDNA to investigate the change in conductance that occurs if a single base pair, a single base, or two separate bases in the stack are modified. All measurements are carried out in aqueous solution with the DNA chemically bound to the electrodes. These measurements demonstrate that the presence of a single base pair mismatch can be identified by the conductance of the molecule and can cause a change in the conductance of dsDNA by as much as an order of magnitude, depending on the specific details of the double helix and the single nucleotidepolymorphism. PMID:16284253

Many wild Atlantic salmon (Salmo salar) populations are threatened by introgressive hybridization from domesticated fish that have escaped from aquaculture facilities. A detailed understanding of the hybridization dynamics between wild salmon and aquaculture escapees requires discrimination of different hybrid classes; however, markers currently available to discriminate the two types of parental genome have limited power to do this. Using a high-density Atlantic salmon single nucleotidepolymorphism (SNP) array, in combination with pooled-sample allelotyping and an Fst outlier approach, we identified 200 SNPs that differentiated an important Atlantic salmon stock from the escapees potentially hybridizing with it. By simulating multiple generations of wild-escapee hybridization, involving wild populations in two major phylogeographic lineages and a genetically diverse set of escapees, we showed that both the complete set of SNPs and smaller subsets could reliably assign individuals to different hybrid classes up to the third hybrid (F3) generation. This set of markers will be a useful tool for investigating the genetic interactions between native wild fish and aquaculture escapees in many Atlantic salmon populations. PMID:27606009

A genomewide linkage scan was carried out in eight clinical samples of informative schizophrenia families. After all quality control checks, the analysis of 707 European-ancestry families included 1,615 affected and 1,602 unaffected genotyped individuals, and the analysis of all 807 families included 1900 affected and 1839 unaffected individuals. Multipoint linkage analysis with correction for marker-marker linkage disequilibrium was carried out with 5,861 single nucleotidepolymorphisms (SNPs; Illumina 4.0 linkage map). Suggestive evidence for linkage (European families) was observed on chromosomes 8p21, 8q24.1, 9q34 and 12q24.1 in non-parametric and/or parametric analyses. In a logistic regression allele-sharing analysis of linkage allowing for intersite heterogeneity, genomewide significant evidence for linkage was observed on chromosome 10p12. Significant heterogeneity was also observed on chromosome 22q11.1. Evidence for linkage across family sets and analyses was most consistent on chromosome 8p21, with a one-lod support interval that does not include the candidate gene NRG1, suggesting that one or more other susceptibility loci might exist in the region. In this era of genomewide association and deep resequencing studies, consensus linkage regions deserve continued attention, given that linkage signals can be produced by many types of genomic variation, including any combination of multiple common or rare SNPs or copy number variants in a region. PMID:19223858

Single nucleotidepolymorphism (SNP) markers were used in the largest cassava (Manihot esculenta Crantz) germplasm collection from Brazil to develop core collections based on the maximization strategy. Subsets with 61, 64, 84, 128, 256, and 384 cassava accessions were selected and named PoHEU, MST64, PoRAN, MST128, MST256, and MST384, respectively. All the 798 alleles identified by 402 SNP markers in the entire collection were captured in all core collections. Only small alterations in the diversity parameters were observed for the different core collections compared with the complete collection. Because of the optimal adjustment of the validation parameters representative of the complete collection, the absence of genotypes with high genetic similarity and the maximization of the genetic distances between accessions of the PoHEU core collection, which contained 4.7% of the accessions of the complete collection, maximized the genetic conservation of this important cassava collection. Furthermore, the development of this core collection will allow concentrated efforts toward future characterization and agronomic evaluation of accessions to maximize the diversity and genetic gains in cassava breeding programs. PMID:25158266

In clinical diagnostics, single nucleotidepolymorphism (SNP)-based microarray analysis enables the detection of copy number variations (CNVs), as well as copy number neutral regions, that are absent of heterozygosity throughout the genome. The aim of the present study was to evaluate the effectiveness and sensitivity of SNP‑based microarray analysis in the diagnosis of hydatidiform mole (HM). By using whole‑genome SNP microarray analysis, villous genotypes were detected, and the ploidy of villous tissue was determined to identify HMs. A total of 66 villous tissues and two twin tissues were assessed in the present study. Among these samples, 11 were triploid, one was tetraploid, 23 were abnormal aneuploidy, three were complete genome homozygosity, and the remaining ones were normal ploidy. The most noteworthy finding of the present study was the identification of six partial HMs and three complete HMs from those samples that were not identified as being HMs on the basis of the initial diagnosis of experienced obstetricians. This study has demonstrated that the application of an SNP‑based microarray analysis was able to increase the sensitivity of diagnosis for HMs with partial and complete HMs, which makes the identification of these diseases at an early gestational age possible. PMID:27151252

Circadian rhythm disruptions are prominently associated with bipolar disorder (BD). Circadian rhythms are regulated by the molecular clock, a family of proteins that function together in a transcriptional–translational feedback loop. The CLOCK protein is a key transcription factor of this feedback loop, and previous studies have found that manipulations of the Clock gene are sufficient to produce manic-like behavior in mice (1). The CLOCK 3111T/C single-nucleotidepolymorphism (SNP; rs1801260) is a genetic variation of the human CLOCK gene that is significantly associated with increased frequency of manic episodes in BD patients (2). The 3111T/C SNP is located in the 3′-untranslated region of the CLOCK gene. In this study, we sought to examine the functional implications of the human CLOCK 3111T/C SNP by transfecting a mammalian cell line (mouse embryonic fibroblasts isolated from Clock−/− knockout mice) with pcDNA plasmids containing the human CLOCK gene with either the T or C SNP at position 3111. We then measured circadian gene expression over a 24-h time period. We found that the CLOCK3111C SNP resulted in higher mRNA levels than the CLOCK 3111T SNP. Furthermore, we found that Per2, a transcriptional target of CLOCK, was also more highly expressed with CLOCK 3111C expression, indicating that the 3′-UTR SNP affects the expression, function, and stability of CLOCK mRNA. PMID:27148095

The optimal management of the commercially important, but mostly over-exploited, pelagic tunas, albacore (Thunnus alalunga Bonn., 1788) and Atlantic bluefin tuna (BFT; Thunnus thynnus L., 1758), requires a better understanding of population structure than has been provided by previous molecular methods. Despite numerous studies of both species, their population structures remain controversial. This study reports the development of single nucleotidepolymorphisms (SNPs) in albacore and BFT and the application of these SNPs to survey genetic variability across the geographic ranges of these tunas. A total of 616 SNPs were discovered in 35 albacore tuna by comparing sequences of 54 nuclear DNA fragments. A panel of 53 SNPs yielded FST values ranging from 0.0 to 0.050 between samples after genotyping 460 albacore collected throughout the distribution of this species. No significant heterogeneity was detected within oceans, but between-ocean comparisons (Atlantic, Pacific and Indian oceans along with Mediterranean Sea) were significant. Additionally, a 17-SNP panel was developed in Atlantic BFT by cross-species amplification in 107 fish. This limited number of SNPs discriminated between samples from the two major spawning areas of Atlantic BFT (FST = 0.116). The SNP markers developed in this study can be used to genotype large numbers of fish without the need for standardizing alleles among laboratories. PMID:23668670

The large majority of human immunodeficiency virus type 1 (HIV-1) markers of disease progression/severity previously identified have been associated with alterations in host genetic and immune responses, with few studies focused on viral genetic markers correlate with changes in disease severity. This study presents a cross-sectional/longitudinal study of HIV-1 single nucleotidepolymorphisms (SNPs) contained within the viral promoter or long terminal repeat (LTR) in patients within the Drexel Medicine CNS AIDS Research and Eradication Study (CARES) Cohort. HIV-1 LTR SNPs were found to associate with the classical clinical disease parameters CD4+ T-cell count and log viral load. They were found in both defined and undefined transcription factor binding sites of the LTR. A novel SNP identified at position 108 in a known COUP (chicken ovalbumin upstream promoter)/AP1 transcription factor binding site was significantly correlated with binding phenotypes that are potentially the underlying cause of the associated clinical outcome (increase in viral load and decrease in CD4+ T-cell count). PMID:27100290

Histophilus somni, a causative agent of the bovine respiratory disease complex, can also cause a variety of systemic disorders, including bronchopneumonia, myocarditis, pericarditis, arthritis, pleuritis, and infectious thrombotic meningoencephalitis. The purpose of this study was to determine if currently circulating strains differ from those of the 1980s by identifying genomic changes. Single nucleotidepolymorphisms (SNPs) and insertion and deletion (INDEL) sites were examined by whole-genome sequencing in 12 samples, 6 old and 6 new. The 31 028 SNP/INDELs recorded were compared against the reference genome sequence of the pathogenic H. somni strain 2336. The distribution of about 75% of these SNPs within a specified gene differed between old and new isolates and did not follow any particular pattern. The other 25% clustered into 2 groups containing the same SNPs in various genes: group I included 5 old isolates and 1 new isolate; group II included 5 new isolates and 1 old isolate. For putative virulence genes there were more SNPs in group I compared with strain 2336, itself an older isolate, than in group II. Although only 25% of all the SNPs formed 2 clusters, the results suggest some genetic difference in various genes between old and new strains. PMID:26130851

Single nucleotidepolymorphisms (SNPs) and simple sequence repeats (SSR) are abundant and evenly distributed co-dominant molecular markers in plant genomes. SSRs are valuable for marker assisted breeding and positional cloning of genes associated traits of interest. Although several high throughput platforms have been developed to identify SNP and SSR markers for analysis of segregant plant populations, breeding in garden asparagus (Asparagus officinalis L.) has been limited by a low content of such markers. In this study massively parallel GS-FLX pyro-sequencing technology (454 Life Sciences) has been used to sequence and compare transcriptome from two genotypes: a rust tolerant male (1770) and a susceptible female (G190). A total of 122,963 and 99,368 sequence reads, with an average length of 245.7bp, have been recovered from accessions 1770 and 190 respectively. A computational pipeline has been used to predict and visually inspect putative SNPs and SSR sequences. Analysis of Gene Ontology (GO) slim annotation assignments for all assembled uniscripts indicated that the 24,403 assemblies represent genes from a broad array of functions. Further, over 1800 putative SNPs and 1000 SSRs were detected. One hundred forty-four SNPs together with 60 selected SSRs were validated and used to develop a preliminary genetic map by using a large BC(1) population, derived from 1770 and G190. The abundance of SNPs and SSRs provides a foundation for the development of saturated genetic maps and their utilization in assisted asparagus breeding programs. PMID:23415335

Defects in the XPG DNA repair endonuclease gene can result in the cancer-prone disorders xeroderma pigmentosum (XP) or the XP–Cockayne syndrome complex. While the XPG cDNA sequence was known, determination of the genomic sequence was required to understand its different functions. In cells from normal donors, we found that the genomic sequence of the human XPG gene spans 30 kb, contains 15 exons that range from 61 to 1074 bp and 14 introns that range from 250 to 5763 bp. Analysis of the splice donor and acceptor sites using an information theory-based approach revealed three splice sites with low information content, which are components of the minor (U12) spliceosome. We identified six alternatively spliced XPG mRNA isoforms in cells from normal donors and from XPG patients: partial deletion of exon 8, partial retention of intron 8, two with alternative exons (in introns 1 and 6) and two that retained complete introns (introns 3 and 9). The amount of alternatively spliced XPG mRNA isoforms varied in different tissues. Most alternative splice donor and acceptor sites had a relatively high information content, but one has the U12 spliceosome sequence. A single nucleotidepolymorphism has allele frequencies of 0.74 for 3507G and 0.26 for 3507C in 91 donors. The human XPG gene contains multiple splice sites with low information content in association with multiple alternatively spliced isoforms of XPG mRNA. PMID:11266544

Single nucleotidepolymorphisms (SNPs) constitute the most common types of genetic variations in the human genome. A number of SNPs have been linked to the development of life threatening diseases including cancer, cardiovascular diseases and neurodegenerative diseases. The ability for ultrasensitive and accurate detection of low abundant disease-related SNPs in bodily fluids (e.g. blood, serum, etc.) holds a significant value in the development of non-invasive future biodiagnostic tools. Over the past two decades, nanomaterials have been utilized in a myriad of biosensing applications due to their ability of detecting extremely low quantities of biologically important biomarkers with high sensitivity and accuracy. Of particular interest is the application of such technologies in the detection of SNPs. The use of various nanomaterials, coupled with different powerful signal amplification strategies, has paved the way for a new generation of ultrasensitive SNP biodiagnostic assays. Over the past few years, several ultrasensitive SNP biosensors capable of detecting specific targets down to the ultra-low regimes (ca. aM and below) and therefore holding great promises for early clinical diagnosis of diseases have been developed. This mini review will highlight some of the most recent, significant advances in nanomaterial-based ultrasensitive SNP sensing technologies capable of detecting specific targets on the attomolar (10–18 M) regime or below. In particular, the design of novel, powerful signal amplification strategies that hold the key to the ultrasensitivity is highlighted. PMID:25785914

Influenza virus (IFV) can evolve rapidly leading to genetic drifts and shifts resulting in human and animal influenza epidemics and pandemics. The genetic shift that gave rise to the 2009 influenza A/H1N1 pandemic originated from a triple gene reassortment of avian, swine and human IFVs. More minor genetic alterations in genetic drift can lead to influenza drug resistance such as the H274Y mutation associated with oseltamivir resistance. Hence, a rapid tool to detect IFV mutations and the potential emergence of new virulent strains can better prepare us for seasonal influenza outbreaks as well as potential pandemics. Furthermore, identification of specific mutations by closely examining single nucleotidepolymorphisms (SNPs) in IFV sequences is essential to classify potential genetic markers associated with potentially dangerous IFV phenotypes. In this study, we developed a novel R library called “SNPer” to analyze quantitative variants in SNPs among IFV subpopulations. The computational SNPer program was applied to three different subpopulations of published IFV genomic information. SNPer queried SNPs data and grouped the SNPs into (1) universal SNPs, (2) likely common SNPs, and (3) unique SNPs. SNPer outperformed manual visualization in terms of time and labor. SNPer took only three seconds with no errors in SNP comparison events compared with 40 hours with errors using manual visualization. The SNPer tool can accelerate the capacity to capture new and potentially dangerous IFV strains to mitigate future influenza outbreaks. PMID:25876137

Chimpanzee populations are diminishing as a consequence of human activities, and as a result this species is now endangered. In the context of conservation programmes, genetic data can add vital information, for instance on the genetic diversity and structure of threatened populations. Single nucleotidepolymorphisms (SNP) are biallelic markers that are widely used in human molecular studies and can be implemented in efficient microarray systems. This technology offers the potential of robust, multiplexed SNP genotyping at low reagent cost in other organisms than humans, but it is not commonly used yet in wild population studies. Here, we describe the characterization of new SNPs in Y-chromosomal intronic regions in chimpanzees and also identify SNPs from mitochondrial genes, with the aim of developing a microarray system that permits the simultaneous study of both paternal and maternal lineages. Our system consists of 42 SNPs for the Y chromosome and 45 SNPs for the mitochondrial genome. We demonstrate the applicability of this microarray in a captive population where genotypes accurately reflected its large pedigree. Two wild-living populations were also analysed and the results show that the microarray will be a useful tool alongside microsatellite markers, since it supplies complementary information about population structure and ecology. SNP genotyping using microarray technology, therefore, is a promising approach and may become an essential tool in conservation genetics to help in the management and study of captive and wild-living populations. Moreover, microarrays that combine SNPs from different genomic regions could replace microsatellite typing in the future. PMID:21585830

It has been suggested that single nucleotidepolymorphisms (SNPs) in genes involved in Toll-like receptors (TLRs) pathway may exhibit broad effects on function of this network and might contribute to a range of human diseases. However, the extent to which these variations affect TLR signaling is not well understood. In this study, we adopted a bioinformatics approach to predict the consequences of SNPs in TLRs network. The consequences of non-synonymous coding SNPs (nsSNPs) were predicted by SIFT, PolyPhen, PANTHER, SNPs&GO, I-Mutant, ConSurf and NetSurf tools. Structural visualization of wild type and mutant protein was performed using the project HOPE and Swiss PDB viewer. The influence of 5'-UTR and 3'- UTR SNPs were analyzed by appropriate computational approaches. Nineteen nsSNPs in TLRs pathway genes were found to have deleterious consequences as predicted by the combination of different algorithms. Moreover, our results suggested that SNPs located at UTRs of TLRs pathway genes may potentially influence binding of transcription factors or microRNAs. By applying a pathway-based bioinformatics analysis of genetic variations, we provided a prioritized list of potentially deleterious variants. These findings may facilitate the selection of proper variants for future functional and/or association studies. PMID:27478803

Apart from water, tea is the world’s most widely consumed beverage. Tea is produced in more than 50 countries with an annual production of approximately 4.7 million tons. The market segment for specialty tea has been expanding rapidly owing to increased demand, resulting in higher revenues and profits for tea growers and the industry. Accurate varietal identification is critically important to ensure traceability and authentication of premium tea products, which in turn contribute to on-farm conservation of tea genetic diversity. Using a set of single nucleotidepolymorphism (SNP) markers developed from the expressed sequence tag (EST) database of Camilla senensis, we genotyped deoxyribonucleic acid (DNA) samples extracted from a diverse group of tea varieties, including both fresh and processed commercial loose-leaf teas. The validation led to the designation of 60 SNPs that unambiguously identified all 40 tested tea varieties with high statistical rigor (p<0.0001). Varietal authenticity and genetic relationships among the analyzed cultivars were further characterized by ordination and Bayesian clustering analysis. These SNP markers, in combination with a high-throughput genotyping protocol, effectively established and verified specific DNA fingerprints for all tested tea varieties. This method provides a powerful tool for variety authentication and quality control for the tea industry. It is also highly useful for the management of tea genetic resources and breeding, where accurate and efficient genotype identification is essential. PMID:26504544

Background Single nucleotidepolymorphisms (SNPs) are the foundation of powerful complex trait and pharmacogenomic analyses. The availability of large SNP databases, however, has emphasized a need for inexpensive SNP genotyping methods of commensurate simplicity, robustness, and scalability. We describe a solution-based, microtiter plate method for SNP genotyping of human genomic DNA. The method is based upon allele discrimination by ligation of open circle probes followed by rolling circle amplification of the signal using fluorescent primers. Only the probe with a 3' base complementary to the SNP is circularized by ligation. Results SNP scoring by ligation was optimized to a 100,000 fold discrimination against probe mismatched to the SNP. The assay was used to genotype 10 SNPs from a set of 192 genomic DNA samples in a high-throughput format. Assay directly from genomic DNA eliminates the need to preamplify the target as done for many other genotyping methods. The sensitivity of the assay was demonstrated by genotyping from 1 ng of genomic DNA. We demonstrate that the assay can detect a single molecule of the circularized probe. Conclusions Compatibility with homogeneous formats and the ability to assay small amounts of genomic DNA meets the exacting requirements of automated, high-throughput SNP scoring. PMID:11511324

This study aimed to evaluate the effects of single nucleotidepolymorphisms (SNPs) in candidate genes for meat quality using a custom 96-SNP panel (Illumina Vera Code GoldenGate Assay) on 15 traits collected from 400 commercial pigs. Meat quality measurements included muscle pH, color (L*, a* and b*), drip loss, cooking loss, peak shear force and six sensory traits including appearance (outside and inside), tenderness, juiciness, flavor and overall liking as well as carcass weight and probe yield. Thirty-five SNPs with minor allele frequencies > 0.10 remained for the multimarker association using the GLM procedure of sas 9.2. Results showed that 20 SNPs were significantly associated with at least one of the traits with either additive or dominance or both effects (P < 0.05). Among these significant SNPs, five of them in ADIPOQ, FTO, TNF, LEPR and AMPD1 had an effect on more than three traits simultaneously; those in MC4R, CAST, DGAT1 and MYF6 had an effect on two traits, while the others were associated with one trait. The results suggest that these markers could be incorporated into commercial pigs for marker-assisted selection and breeding programs for carcass and meat quality trait improvement. PMID:24707962

Major facilitators of water movement through plant cell membranes include aquaporin proteins. Wheat is among the largest and most important cereal crops worldwide; however, unlike other model plants such as rice, maize and Arabidopsis, little has been reported on wheat major intrinsic proteins (MIPs). This study presents a comprehensive computational identification of 349 new wheat expressed sequence tags (ESTs), encoding 13 wheat aquaporin genes. Identified aquaporins consist of 6 plasma membrane intrinsic proteins (PIP) and 1 TIP showing high sequence similarity with rice aquaporins. We also identified 4 NOD26-like intrinsic proteins (NIP) and 2 SIP members that showed more divergence. Further, expression analysis of the aquaporin genes using the available EST information in UniGene revealed their transcripts were differentially regulated in various stress- and tissue-specific libraries. Allele specific Polymerase chain reaction (PCR) primers based on single nucleotidepolymorphism (SNP) were designed using PIP as the target gene and validated on a core set of Indian wheat genotypes. A 3D theoretical model of the wheat aquaporin protein was built by homology modeling and could prove to be useful in the further functional characterization of this protein. Collectively with expression and bioinformatics analysis, our results support the idea that the genes identified in this study signify an important genetic resource providing potential targets to modify the water use properties of wheat. PMID:24250219

The large majority of human immunodeficiency virus type 1 (HIV-1) markers of disease progression/severity previously identified have been associated with alterations in host genetic and immune responses, with few studies focused on viral genetic markers correlate with changes in disease severity. This study presents a cross-sectional/longitudinal study of HIV-1 single nucleotidepolymorphisms (SNPs) contained within the viral promoter or long terminal repeat (LTR) in patients within the Drexel Medicine CNS AIDS Research and Eradication Study (CARES) Cohort. HIV-1 LTR SNPs were found to associate with the classical clinical disease parameters CD4+ T-cell count and log viral load. They were found in both defined and undefined transcription factor binding sites of the LTR. A novel SNP identified at position 108 in a known COUP (chicken ovalbumin upstream promoter)/AP1 transcription factor binding site was significantly correlated with binding phenotypes that are potentially the underlying cause of the associated clinical outcome (increase in viral load and decrease in CD4+ T-cell count). PMID:27100290

Nonmelanoma skin cancer (NMSC) is the most common cancer in the U.S.A. The two most common NMSCs are basal cell carcinoma and squamous cell carcinoma. The associations of single-nucleotidepolymorphisms (SNPs) in pigmentation pathway genes with NMSC are not well characterized. There is a series of epidemiological studies that have tested these relationships, but there is no recent summary of these findings. To explain overarching trends, we undertook a systematic review of published studies. The summarized data support the concept that specific SNPs in the pigmentation pathway are of importance for the pathogenesis of NMSC. The SNPs with the most promising evidence include MC1R rs1805007(T) (Arg151Cys) and rs1805008(T) (Arg160Trp), and ASIP AH haplotype [rs4911414(T) and rs1015362(G)]. There are a few other SNPs found in TYR, OCA2 and SLC45A2 that may show additional correlation after future research. With additional research there is potential for the translation of future findings to the clinic in the form of SNP screenings, where patients at high risk for NMSC can be identified beyond their phenotype by genotypically screening for predisposing SNPs. PMID:25319428

We developed a new approach for pairwise kinship analysis in forensic genetics based on chromosomal sharing between two individuals. Here, we defined “index of chromosome sharing” (ICS) calculated using 174,254 single nucleotidepolymorphism (SNP) loci typed by SNP microarray and genetic length of the shared segments from the genotypes of two individuals. To investigate the expected ICS distributions from first- to fifth-degree relatives and unrelated pairs, we used computationally generated genotypes to consider the effect of linkage disequilibrium and recombination. The distributions were used for probabilistic evaluation of the pairwise kinship analysis, such as likelihood ratio (LR) or posterior probability, without allele frequencies and haplotype frequencies. Using our method, all actual sample pairs from volunteers showed significantly high LR values (i.e., ≥ 108); therefore, we can distinguish distant relationships (up to the fifth-degree) from unrelated pairs based on LR. Moreover, we can determine accurate degrees of kinship in up to third-degree relationships with a probability of > 80% using the criterion of posterior probability ≥ 0.90, even if the kinship of the pair is totally unpredictable. This approach greatly improves pairwise kinship analysis of distant relationships, specifically in cases involving identification of disaster victims or missing persons. PMID:27472558

The development of simple, inexpensive, hand-held, user-friendly biosensor for high throughput and multiplexed genotyping of various single nucleotidepolymorphisms (SNPs) in a single run experiment by a nonspecialist user is the main challenge in the analysis of DNA. Visualizing the signal and possibility to monitor SNPs by a digital camera opens a new horizon for the routine applications. In the present manuscript, a novel wireless electrochemiluminescence (ECL) DNA array is introduced for the visualized genotyping of different SNPs on the basis of ECL of luminol/hydrogen peroxide system on a bipolar electrode (BPE) array platform. After modification of anodic poles of the array with the DNA probe and its hybridization with the targets, genotyping of various SNPs is carried out by exposing the array to different monobase modified luminol-platinum nanoparticles (M-L-PtNPs). Upon the hybridization of M-L-PtNPs to mismatch sites, the ECL of luminol is followed using a photomultiplier tube (PMT) or digital camera and the images are analyzed by ImageJ software. This biosensor can detect even thermodynamically stable SNP (G-T mismatches) in the range of 2-600 pM. Also, by combining the advantages of BPE and the high visual sensitivity of ECL, it could be easily expected to achieve sensitive screening of different SNPs. The present biosensor demonstrates the capability for the discrimination between PCR products of normal, heterozygous, and homozygous beta thalassemia genetic disorders. PMID:26176414

The duck is one of the most economically important waterfowl as a source of meat, eggs, and feathers. Characterizing the genetic variation in duck species is an important step toward linking genes or genomic regions with phenotypes. Human-driven selection during duck domestication and subsequent breed formation has likely left detectable signatures in duck genome. In this study, we employed a panel of >1.4 million single-nucleotidepolymorphisms (SNPs) identified from the RNA sequencing (RNA-seq) data of 15 duck individuals. The density of the resulting SNPs is significantly positively correlated with the density of genes across the duck genome, which demonstrates that the usage of the RNA-seq data allowed us to enrich variant functional categories, such as coding exons, untranslated regions (UTRs), introns, and downstream/upstream. We performed a complete scan of selection signatures in the ducks using the composite likelihood ratio (CLR) and found 76 candidate regions of selection, many of which harbor genes related to phenotypes relevant to the function of the digestive system and fat metabolism, including TCF7L2, EIF2AK3, ELOVL2, and fatty acid-binding protein family. This study illustrates the potential of population genetic approaches for identifying genomic regions affecting domestication-related phenotypes and further helps to increase the known genetic information about this economically important animal. PMID:26819540

Varicella zoster virus (VZV) is one of the human herpesviruses. To date, over 40 complete VZV genomes have been sequenced and analyzed. The VZV genome contains around 125,000 base pairs including 70 open reading frames (ORFs). Enumeration of single nucleotidepolymorphisms (SNPs) has determined that the following ORFs are the most variable (in descending order): 62, 22, 29, 28, 37, 21, 54, 31, 1 and 55. ORF 62 is the major immediate early regulatory VZV gene. Further SNP analysis across the entire genome has led to the observation that VZV strains can be broadly grouped into clades within a phylogenetic tree. VZV strains collected in Singapore provided important sequence data for construction of the phylogenetic tree. Currently 5 VZV clades are recognized; they have been designated clades 1 through 5. Clades 1 and 3 include European/North American strains; clade 2 includes Asian strains, especially from Japan; and clade 5 includes strains from India. Clade 4 includes some strains from Europe, but its geographic origins need further documentation.. Within clade 1, five variant viruses have been isolated with a missense mutation in the gE (ORF 68) glycoprotein; these strains have an altered increased cell spread phenotype. Bioinformatics analyses of the attenuated vaccine strains have also been performed, with a subsequent discovery of a stop-codon SNP in ORFO as a likely attenuation determinant. Taken together, these VZV bioinformatics analyses have provided enormous insights into VZV phylogenetics as well as VZV SNPs associated with attenuation. PMID:23183312

Microsatellite markers are difficult to apply within lepidopteran studies due to the lack of locus-specific PCR amplification and the high proportion of “null” alleles, such that erroneous estimations of population genetic parameters often result. Herein single nucleotidepolymorphism (SNP) markers are developed from Ostrinia nubilalis (Lepidoptera: Crambidae) using next generation expressed sequence tag (EST) data. A total of 2742 SNPs were predicted within a reference assembly of 7414 EST contigs, and a subset of 763 were incorporated into 24 multiplex PCR reactions. To validate this pipeline, 5 European and North American sample sites were genotyped at 178 SNP loci, which indicated 84 (47.2%) were in Hardy–Weinberg equilibrium. Locus-by-locus FST, analysis of molecular variance, and STRUCTURE analyses indicate significant genetic differentiation may exist between European and North American O. nubilalis. The observed genetic diversity was significantly lower among European sites, which may result from genetic drift, natural selection, a genetic bottleneck, or ascertainment bias due to North American origin of EST sequence data. SNPs are an abundant source of mutation data for molecular genetic marker development in non-model species, with shared ancestral SNPs showing application within closely related species. These markers offer advantages over microsatellite markers for genetic and genomic analyses of Lepidoptera, but the source of mutation data may affect the estimation of population parameters and likely need to be considered in the interpretation of empirical data. PMID:22303334

Chromosomal abnormalities are important for the risk stratification of acute lymphoblastic leukemia/lymphoma (ALL). However, approximately 30% of pediatric and 50% of adult patients lack abnormalities with clinical relevance by traditional cytogenetic analysis. We integrated cytogenetic, fluorescence in situ hybridization, and whole-genome single-nucleotidepolymorphism array results from 60 consecutive clinical ALL cases. By cytogenetic and/or fluorescence in situ hybridization analyses, recurring abnormalities with clinical relevance were observed in 33 B-cell ALL (B-ALL), including t(9;22), hyperdiploidy, KMT2A translocation, ETV6-RUNX1, intrachromosomal amplification of chromosome 21, near haploidy or low hypodiploidy, and t(8;22). Single-nucleotidepolymorphism array analysis found additional aberrations with prognostic or therapeutic implication in 21 B-ALL and two T-cell ALL, including IKZF1 deletion, intrachromosomal amplification of chromosome 21 (one case with a normal karyotype), low hypodiploidy (two cases with a normal karyotype), and one case each with fusion genes ETV6-NTRK3, CRLF2-P2RY8, NUP214-ABL1, and SET-NUP214. IKZF1 deletion was noted in nine B-ALL with t(9;22), one B-ALL with t(4;11), five B-ALL with a normal karyotype, and three B-ALL with nonrecurring karyotypic abnormalities. Combining single-nucleotidepolymorphism array with chromosome and fluorescence in situ hybridization assays, the detection rate for clinically significant abnormal results increased from 56% to 75%. Whole-genome single-nucleotidepolymorphism array analysis detects cytogenetically undetectable clinically significant aberrations and should be routinely applied at diagnosis of ALL. PMID:27161658

Nucleotide variation in an 8.1-kb fragment encompassing the RpII215 gene, which encodes the largest subunit of the RNA polymerase II complex, is analyzed in a sample of 11 chromosomes from a natural population of Drosophila subobscura. No amino acid polymorphism was detected among the 157 segregating sites. The observed numbers of preferred and unpreferred derived synonymous mutations can be explained by neutral mutational processes. In contrast, preferred mutations segregate at significantly higher frequency than unpreferred mutations, suggesting the action of natural selection. The polymorphism to divergence ratio is different for preferred and unpreferred changes, in agreement with their beneficial and deleterious effects on fitness, respectively. Preferred and unpreferred codons are nonrandomly distributed in the RpII215 gene, leading to a heterogeneous distribution of polymorphic to fixed synonymous differences across this coding region. This intragenic variation of the polymorphism/divergence ratio cannot be explained by different patterns of gene expression, mutation, or recombination rates, and therefore it indicates that selection coefficients for synonymous mutations can vary extensively across a coding region. The application of nucleotide composition stationarity tests in coding and flanking noncoding regions, assumed to behave neutrally, allows the detection of the action of natural selection when stationarity holds in the noncoding region. PMID:10880485

Background General, breed- and diet-dependent associations between feed efficiency in beef cattle and single nucleotidepolymorphisms (SNPs) or haplotypes were identified on a population of 1321 steers using a 50 K SNP panel. Genomic associations with traditional two-step indicators of feed efficiency – residual feed intake (RFI), residual average daily gain (RADG), and residual intake gain (RIG) – were compared to associations with two complementary one-step indicators of feed efficiency: efficiency of intake (EI) and efficiency of gain (EG). Associations uncovered in a training data set were evaluated on independent validation data set. A multi-SNP model was developed to predict feed efficiency. Functional analysis of genes harboring SNPs significantly associated with feed efficiency and network visualization aided in the interpretation of the results. Results For the five feed efficiency indicators, the numbers of general, breed-dependent, and diet-dependent associations with SNPs (P-value nucleotide binding; ion transport, phosphorous metabolic process, and the MAPK signaling pathway were overrepresented among the genes harboring the SNPs associated with feed efficiency. Conclusions The general SNP associations suggest that a single panel of genomic variants can be used regardless of breed and diet. The breed- and diet

Diacylglycerol O-acyltransferase 1 (DGAT1) is a microsomal enzyme that catalyzes the final step of triglyceride synthesis. The DGAT1 gene is a strong functional candidate for determining milk fat content in cattle. In this work, we used PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) and DNA sequencing to examine polymorphism in the region spanning exon 7 to exon 9 of the DGAT1 gene in Murrah and Pandharpuri buffaloes. Three alleles (A, B and C) and four novel single-nucleotidepolymorphisms were identified in the buffalo DGAT1 gene. The frequencies of the alleles differed between the two buffalo breeds, with allele C being present in Murrah but not in Pandharpuri buffalo. The allele variation detected in this work may influence DGAT1 expression and function. The results described here could be useful in examining the association between the DGAT1 gene and milk traits in buffalo. PMID:23055800

Multidrug resistance gene 1 (MDR1) is known for its involvement in the detoxification through the active transport of toxic compounds from diverse origins outside the cells. These compounds could cause injury to cell DNA, which might lead in cancer like chronic myeloid leukemia (CML). Individual inherited genetic differences related to polymorphism in detoxification enzymes could be an important factor not only in carcinogen metabolism but also in susceptibility of cancer. The present study aimed to investigate the association of three single nucleotidepolymorphisms (SNPs) of the MDR1 gene in the susceptibility of CML. We successively have determined the genotype profiles of 1236 C>T (exon 12); 2677 G>T (exon 21), and 3435 C>T (exon 26) SNPs by PCR-RFLP in 89 patients and 99 unrelated healthy controls. Logistic regression was used to assess the effect of each SNP on the development of CML. Interestingly, in exon 12, the 1236 TT was significantly associated with the susceptibility of CML when compared to the wild type 1236 CC (OR 2.7; 95% CI 1-7.32, p = 0.041). Additionally, the recessive model 1236 TT vs. 1236 CC/CT showed a risk of 3.3 fold (p = 0.011) with CML. In exon 26, the 3435 CT genotype was associated with a reduced risk of CML (OR 0.5; 95% CI 0.3-1, p = 0.042). In exon 21, the 2677 GT genotype seems to have a protective effect (OR 0.6; 95% CI 0.32-1.1, p = 0.074). Diplolotypes analysis has demonstrated no effect in susceptibility of CML, but 1236 CT/3435 CC and 1236 CC/2677 GT were associated with a protective effect. The haplotypes analysis showed no particular trend (global association p = 0.33). Our findings demonstrate that 1236 TT in exon 12 might contribute in the susceptibility of CML, while the 3435 CT in exon 26 as well as 1236 CT/3435 CC and 1236 CC/2677 GT combinations might be protective factors. PMID:25087925

Background To enhance capabilities for genomic analyses in rainbow trout, such as genomic selection, a large suite of polymorphic markers that are amenable to high-throughput genotyping protocols must be identified. Expressed Sequence Tags (ESTs) have been used for single nucleotidepolymorphism (SNP) discovery in salmonids. In those strategies, the salmonid semi-tetraploid genomes often led to assemblies of paralogous sequences and therefore resulted in a high rate of false positive SNP identification. Sequencing genomic DNA using primers identified from ESTs proved to be an effective but time consuming methodology of SNP identification in rainbow trout, therefore not suitable for high throughput SNP discovery. In this study, we employed a high-throughput strategy that used pyrosequencing technology to generate data from a reduced representation library constructed with genomic DNA pooled from 96 unrelated rainbow trout that represent the National Center for Cool and Cold Water Aquaculture (NCCCWA) broodstock population. Results The reduced representation library consisted of 440 bp fragments resulting from complete digestion with the restriction enzyme HaeIII; sequencing produced 2,000,000 reads providing an average 6 fold coverage of the estimated 150,000 unique genomic restriction fragments (300,000 fragment ends). Three independent data analyses identified 22,022 to 47,128 putative SNPs on 13,140 to 24,627 independent contigs. A set of 384 putative SNPs, randomly selected from the sets produced by the three analyses were genotyped on individual fish to determine the validation rate of putative SNPs among analyses, distinguish apparent SNPs that actually represent paralogous loci in the tetraploid genome, examine Mendelian segregation, and place the validated SNPs on the rainbow trout linkage map. Approximately 48% (183) of the putative SNPs were validated; 167 markers were successfully incorporated into the rainbow trout linkage map. In addition, 2% of the

Spatial distribution of single-nucleotidepolymorphisms (SNPs) related to fungicide resistance was studied for Botrytis cinerea populations in vineyards and for B. squamosa populations in onion fields. Heterogeneity in this distribution was characterized by performing geostatistical analyses based on semivariograms and through the fitting of discrete probability distributions. Two SNPs known to be responsible for boscalid resistance (H272R and H272Y), both located on the B subunit of the succinate dehydrogenase gene, and one SNP known to be responsible for dicarboximide resistance (I365S) were chosen for B. cinerea in grape. For B. squamosa in onion, one SNP responsible for dicarboximide resistance (I365S homologous) was chosen. One onion field was sampled in 2009 and another one was sampled in 2010 for B. squamosa, and two vineyards were sampled in 2011 for B. cinerea, for a total of four sampled sites. Cluster sampling was carried on a 10-by-10 grid, each of the 100 nodes being the center of a 10-by-10-m quadrat. In each quadrat, 10 samples were collected and analyzed by restriction fragment length polymorphism polymerase chain reaction (PCR) or allele specific PCR. Mean SNP incidence varied from 16 to 68%, with an overall mean incidence of 43%. In the geostatistical analyses, omnidirectional variograms showed spatial autocorrelation characterized by ranges of 21 to 1 m. Various levels of anisotropy were detected, however, with variograms computed in four directions (at 0°, 45°, 90°, and 135° from the within-row direction used as reference), indicating that spatial autocorrelation was prevalent or characterized by a longer range in one direction. For all eight data sets, the β-binomial distribution was found to fit the data better than the binomial distribution. This indicates local aggregation of fungicide resistance among sampling units, as supported by estimates of the parameter θ of the β-binomial distribution of 0.09 to 0.23 (overall median value = 0

Background Genetic information based on molecular markers has increasingly being used in cattle breeding improvement programmes, as a mean to improve conventionally phenotypic selection. Advances in molecular genetics have led to the identification of several genetic markers associated with genes affecting economic traits. Until recently, the identification of the causative genetic variants involved in the phenotypes of interest has remained a difficult task. The advent of novel sequencing technologies now offers a new opportunity for the identification of such variants. Despite sequencing costs plummeting, sequencing whole-genomes or large targeted regions is still too expensive for most laboratories. A transcriptomic-based sequencing approach offers a cheaper alternative to identify a large number of polymorphisms and possibly to discover causative variants. In the present study, we performed a gene-based single nucleotidepolymorphism (SNP) discovery analysis in bovine Longissimus thoraci, using RNA-Seq. To our knowledge, this represents the first study done in bovine muscle. Results Messenger RNAs from Longissimus thoraci from three Limousin bull calves were subjected to high-throughput sequencing. Approximately 36–46 million paired-end reads were obtained per library. A total of 19,752 transcripts were identified and 34,376 different SNPs were detected. Fifty-five percent of the SNPs were found in coding regions and ~22% resulted in an amino acid change. Applying a very stringent SNP quality threshold, we detected 8,407 different high-confidence SNPs, 18% of which are non synonymous coding SNPs. To analyse the accuracy of RNA-Seq technology for SNP detection, 48 SNPs were selected for validation by genotyping. No discrepancies were observed when using the highest SNP probability threshold. To test the usefulness of the identified SNPs, the 48 selected SNPs were assessed by genotyping 93 bovine samples, representing mostly the nine major breeds used in France

We present a novel and simple method to manipulate droplets applicable to an open-surface microfluidic platform. The platform comprised a control module for pneumatic droplets and a superhydrophobic polydimethylsiloxane (PDMS) membrane. With pneumatic suction to cause deflection of the flexible PDMS-based superhydrophobic membrane, the sample and reagent droplets on the membrane become transported and mixed. A facile one-step laser micromachining technique serves to fabricate a superhydrophobic surface; a contact angle of 150° and a hysteresis angle of 4° were achieved without chemical modification. Relative to previous open-surface microfluidic systems, this platform is capable of simultaneous and precise delivery of droplets in two-dimensional (2D) manipulation. Droplets were manipulated with suction, which avoided interference from an external driving energy (e.g. heat, light, electricity) to affect the bio-sample inside the droplets. Two common bio-samples, namely protein and DNA, verified the performance of the platform. Based on the experimental results, operations on protein can be implemented without adsorption on the surface of the platform. Another striking result is the visual screening for multi-nucleotidepolymorphism with hybridization-mediated growth of gold-nanoparticle (AuNP) probes. The detection results are observable with the naked eye, without the aid of advanced instruments. The entire procedure only takes 5 min from the addition of the sample and reagent to obtaining the results, which is much quicker than the traditional method. The total sample volume consumed in each operation is only 10 μL, which is significantly less than what is required in a large system. According to this approach, the proposed platform is suitable for biological and chemical applications. PMID:24789224

The α7nicotinic receptor (nAChR) is a major subtype of the nAChRs in the central nervous system, and the receptor plays an important role in brain function. In the dbSNP database, there are 55 single nucleotidepolymorphisms (SNPs) that cause missense mutations of the human α7nAChR in the coding region. In this study, we tested the impact of 14 SNPs that cause missense mutations in the agonist binding site or the coupling region between binding site and channel gate on the receptor function. The wild type or mutant receptors were expressed or co-expressed in Xenopus oocytes, and the agonist-induced currents were tested using two-electrode voltage clamp. Our results demonstrated that 6 mutants were nonfunctional, 4 mutants had reduced current expression, and 1 mutants altered ACh and nicotine efficacy in the opposite direction, and one additional mutant had slightly reduced agonist sensitivity. Interestingly, the function of most of these nonfunctional mutants could be rescued by α7nAChR positive allosteric modulator PNU-120596 and agonist-PAM 4BP-TQS. Finally, when coexpressed with the wild type, the nonfunctional mutants could also influence the receptor function. These changes of the receptor properties by the mutations could potentially have an impact on the physiological function of the α7nAChR-mediated cholinergic synaptic transmission and anti-inflammatory effects in the human SNP carriers. Rescuing the nonfunctional mutants could provide a novel way to treat the related disorders. PMID:26340537

Molecular typing of Mycoplasma pneumoniae is an important tool for identifying grouped cases and investigating outbreaks. In the present study, we developed a new genotyping method based on single nucleotidepolymorphisms (SNPs) selected from the whole-genome sequencing of eight M. pneumoniae strains, using the SNaPshot minisequencing assay. Eight SNPs, localized in housekeeping genes, predicted lipoproteins, and adhesin P1 genes were selected for genotyping. These SNPs were evaluated on 140 M. pneumoniae clinical isolates previously genotyped by multilocus variable-number tandem-repeat analysis (MLVA-5) and adhesin P1 typing. This method was also adapted for direct use with clinical samples and evaluated on 51 clinical specimens. The analysis of the clinical isolates using the SNP typing method showed nine distinct SNP types with a Hunter and Gaston diversity index (HGDI) of 0.836, which is higher than the HGDI of 0.583 retrieved for the MLVA-4 typing method, where the nonstable Mpn1 marker was removed. A strong correlation with the P1 adhesin gene typing results was observed. The congruence was poor between MLVA-5 and SNP typing, indicating distinct genotyping schemes. Combining the results increased the discriminatory power. This new typing method based on SNPs and the SNaPshot technology is a method for rapid M. pneumoniae typing directly from clinical specimens, which does not require any sequencing step. This method is based on stable markers and provides information distinct from but complementary to MLVA typing. The combined use of SNPs and MLVA typing provides powerful discrimination of strains. PMID:26202117

Background: Based on several reports including genome-wide association studies, genetic variability has been linked with higher (nearly half) susceptibility toward coronary artery disease (CAD). We aimed to evaluate the association of chromosome 9p21 single nucleotidepolymorphisms (SNPs): rs2383207, rs10757278, and rs10757274 with the risk and severity of CAD among Arab population. Materials and Methods: A prospective observational case-control study was conducted between 2011 and 2012, in which 236 patients with CAD were recruited from the Heart Hospital in Qatar. Patients were categorized according to their coronary angiographic findings. Also, 152 healthy volunteers were studied to determine if SNPs are associated with risk of CAD. All subjects were genotyped for SNPs (rs2383207, rs2383206, rs10757274 and rs10757278) using allele-specific real-time polymerase chain reaction. Results: Patients with CAD had a mean age of 57 ± 10; of them 77% were males, 54% diabetics, and 25% had family history of CAD. All SNPs were in Hardy-Weinberg equilibrium except rs2383206, with call rate >97%. After adjusting for age, sex and body mass index, the carriers of GG genotype for rs2383207 have increased the risk of having CAD with odds ratio (OR) of 1.52 (95% confidence interval [CI] = 1.01-2.961, P = 0.046). Also, rs2383207 contributed to CAD severity with adjusted OR 1.80 (95% CI = 1.04-3.12, P = 0.035) based on the dominant genetic model. The other SNPs (rs10757274 and rs10757278) showed no significant association with the risk of CAD or its severity. Conclusion: Among Arab population in Qatar, only G allele of rs2483207 SNP is significantly associated with risk of CAD and its severity. PMID:26109989

Acute respiratory distress syndrome (ARDS) is a lung condition characterized by impaired gas exchange with systemic release of inflammatory mediators, causing pulmonary inflammation, vascular leak and hypoxemia. Existing biomarkers have limited effectiveness as diagnostic and therapeutic targets. To identify disease-associating variants in ARDS patients, whole-exome sequencing was performed on 96 ARDS patients, detecting 1,382,399 SNPs. By comparing these exome data to those of the 1000 Genomes Project, we identified a number of single nucleotidepolymorphisms (SNP) which are potentially associated with ARDS. 50,190SNPs were found in all case subgroups and controls, of which89 SNPs were associated with susceptibility. We validated three SNPs (rs78142040, rs9605146 and rs3848719) in additional ARDS patients to substantiate their associations with susceptibility, severity and outcome of ARDS. rs78142040 (C>T) occurs within a histone mark (intron 6) of the Arylsulfatase D gene. rs9605146 (G>A) causes a deleterious coding change (proline to leucine) in the XK, Kell blood group complex subunit-related family, member 3 gene. rs3848719 (G>A) is a synonymous SNP in the Zinc-Finger/Leucine-Zipper Co-Transducer NIF1 gene. rs78142040, rs9605146, and rs3848719 are associated significantly with susceptibility to ARDS. rs3848719 is associated with APACHE II score quartile. rs78142040 is associated with 60-day mortality in the overall ARDS patient population. Exome-seq is a powerful tool to identify potential new biomarkers for ARDS. We selectively validated three SNPs which have not been previously associated with ARDS and represent potential new genetic biomarkers for ARDS. Additional validation in larger patient populations and further exploration of underlying molecular mechanisms are warranted. PMID:25372662

Molecular typing of Mycoplasma pneumoniae is an important tool for identifying grouped cases and investigating outbreaks. In the present study, we developed a new genotyping method based on single nucleotidepolymorphisms (SNPs) selected from the whole-genome sequencing of eight M. pneumoniae strains, using the SNaPshot minisequencing assay. Eight SNPs, localized in housekeeping genes, predicted lipoproteins, and adhesin P1 genes were selected for genotyping. These SNPs were evaluated on 140 M. pneumoniae clinical isolates previously genotyped by multilocus variable-number tandem-repeat analysis (MLVA-5) and adhesin P1 typing. This method was also adapted for direct use with clinical samples and evaluated on 51 clinical specimens. The analysis of the clinical isolates using the SNP typing method showed nine distinct SNP types with a Hunter and Gaston diversity index (HGDI) of 0.836, which is higher than the HGDI of 0.583 retrieved for the MLVA-4 typing method, where the nonstable Mpn1 marker was removed. A strong correlation with the P1 adhesin gene typing results was observed. The congruence was poor between MLVA-5 and SNP typing, indicating distinct genotyping schemes. Combining the results increased the discriminatory power. This new typing method based on SNPs and the SNaPshot technology is a method for rapid M. pneumoniae typing directly from clinical specimens, which does not require any sequencing step. This method is based on stable markers and provides information distinct from but complementary to MLVA typing. The combined use of SNPs and MLVA typing provides powerful discrimination of strains. PMID:26202117

The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify species-specific diagnostic single-nucleotidepolymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N=159) and from the neighboring Faroe Islands (N=29) were genotyped, along with 94 larvae (49 European and 45 American eel) collected in the Sargasso Sea. Our SNP survey showed that the majority of Icelandic eels are pure European eels but there is also an important contribution of individuals of admixed ancestry (10.7%). Although most of the hybrids were identified as F1 hybrids from European eel female × American eel male crosses, backcrosses were also detected, including a first-generation backcross (F1 hybrid × pure European eel) and three individuals identified as second-generation backcrosses originating from American eel × F1 hybrid backcrosses interbreeding with pure European eels. In comparison, no hybrids were observed in the Faroe Islands, the closest bodies of land to Iceland. It is possible that hybrids show an intermediate migratory behaviour between the two parental species that ultimately brings hybrid larvae to the shores of Iceland, situated roughly halfway between the Sargasso Sea and Europe. Only two hybrids were observed among Sargasso Sea larvae, both backcrosses, but no F1 hybrids, that points to temporal variation in the occurrence of hybridization. PMID:24424165

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Our recent study demonstrated that the expression of Wilms' tumor 1 gene (WT1) is associated with surgical outcome in CRC patients. The present study aimed to investigate the genetic association of the single-nucleotidepolymorphism rs16754 in the WT1 gene with the occurrence of CRC, using an age-matched case-control study design. In addition, the correlation between genotype and WT1 expression was investigated. Genomic DNA samples from 104 CRC cases, aged 15–65 years, and 208 healthy controls, were genotyped for rs16754 using the TaqMan genotyping method. The genotype distribution conformed to the Hardy-Weinberg equilibrium (P=0.80). The overall minor allele frequency (MAF) of rs16754 (allele A) was 0.33. The MAF among CRC cases was significantly higher compared with that in controls (0.39 vs. 0.31, respectively; P=0.03). The AA genotype was significantly associated with the disease (odds ratio = 2.51, 95% confidence interval: 1.24–5.07, P=0.01). Cases with the AA genotype exhibited a significantly poorer 3-year overall survival (60%), compared with those with the GG or GA genotypes (80%) (log-rank test, P<0.01). Reverse transcription quantitative polymerase chain reaction analysis demonstrated that the expression of WT1 in tumor tissues was higher compared with that in normal tissue; however, there were no significant differences in its expression among different genotypes. Therefore, rs16754 was found to be associated with the occurrence and prognosis of CRC in our subjects. PMID:26807256

Keloids are abnormally raised fibroproliferative lesions that usually occur following cutaneous traumas. Recently, a large-scale genome-wide association study (GWAS) has identified multiple single nucleotidepolymorphisms (SNPs) in three genetic loci that are associated with keloids in Japanese population. Subsequently, two reported loci 1q41 (rs873549 and rs1442440) and 15q21.3 (rs2271289) for keloids were confirmed in selected Chinese population. The association of these SNPs with clinical features of keloids, has not yet been studied. To explore the role of these SNPs in the pathogenesis of keloids, we performed a case-controlled study in another independent Chinese Han population to analyze the correlation between 4 SNPs (rs873549, rs2118610, rs1511412, rs2271289) and keloids phenotypes. 309 keloids patients and 1080 control subjects were included. The results showed that, in the dominant mode of inheritance, the minor allele T of SNP rs2271289 had significantly higher odd ratios (ORs) in the severe keloid group compared with both the controls and the mild keloid group. The ORs were maintained after Bonferroni's correction (OR: 4.09, 95% CI: 1.78-9.37, P-value 3.25E-04). The ratio of the severe: mild OR for rs2271289 (dominant model) is (4.73/1.84=2.57). Similar associations in SNP rs2271289 were seen for groups with no family history and multiplesite compared with the control groups. No associations between keloid number, family history or severity relative to the controls were observed for the other three SNPs. Our data support that rs2271289 is strongly associated with severe keloids and might contribute to the complexity of clinical features of keloids. PMID:27158346

Variation in the expression of genes with putative roles in wood development was associated with single-nucleotidepolymorphisms (SNPs) using a population of loblolly pine (Pinus taeda L.) that included individuals from much of the native range. Association studies were performed using 3938 SNPs and expression data obtained using quantitative real-time polymerase chain reaction (PCR) (qRT-PCR) for 106 xylem development genes in 400 clonally replicated loblolly pine individuals. A general linear model (GLM) approach, which takes the underlying population structure into consideration, was used to discover significant associations. After adjustment for multiple testing using a false discovery rate correction, 88 statistically significant associations (Q<0.05) were observed for 80 SNPs with the expression data of 33 xylem development genes. Thirty SNPs caused nonsynonymous mutations, 18 resulted in synonymous mutations, 11 were in 3' untranslated regions (UTRs), 1 was in a 5' UTR and 20 were in introns. Using AraNet, we found that Arabidopsis genes with high similarity to the loblolly pine genes involved in 21 of the 88 statistically significant associations are connected in functional gene networks. Comparisons of gene expression values revealed that in most cases the average expression in plants homozygous for the rare SNP allele was lower than that of plants that were heterozygous or homozygous for the abundant allele. Although there are association studies of SNPs and expression profiles for humans, Arabidopsis and white spruce, to the best of our knowledge, this is the first example of such an association genetic study in pines. Functional validation of these associations will lead to a deeper understanding of the molecular basis of phenotypic differences in wood development among individuals in conifer populations. PMID:23933831

Incorporation of genetic variants such as single nucleotidepolymorphisms (SNPs) into risk prediction models may account for a substantial fraction of attributable disease risk. Genetic data, from 2385 subjects recruited into the Liverpool Lung Project (LLP) between 2000 and 2008, consisting of 20 SNPs independently validated in a candidate-gene discovery study was used. Multifactor dimensionality reduction (MDR) and random forest (RF) were used to explore evidence of epistasis among 20 replicated SNPs. Multivariable logistic regression was used to identify similar risk predictors for lung cancer in the LLP risk model for the epidemiological model and extended model with SNPs. Both models were internally validated using the bootstrap method and model performance was assessed using area under the curve (AUC) and net reclassification improvement (NRI). Using MDR and RF, the overall best classifier of lung cancer status were SNPs rs1799732 (DRD2), rs5744256 (IL-18), rs2306022 (ITGA11) with training accuracy of 0.6592 and a testing accuracy of 0.6572 and a cross-validation consistency of 10/10 with permutation testing P<0.0001. The apparent AUC of the epidemiological model was 0.75 (95% CI 0.73-0.77). When epistatic data were incorporated in the extended model, the AUC increased to 0.81 (95% CI 0.79-0.83) which corresponds to 8% increase in AUC (DeLong's test P=2.2e-16); 17.5% by NRI. After correction for optimism, the AUC was 0.73 for the epidemiological model and 0.79 for the extended model. Our results showed modest improvement in lung cancer risk prediction when the SNP epistasis factor was added. PMID:27121382

Rheumatoid arthritis (RA) is a disorder with important public health implications. It is possible that there are clinically distinctive subtypes of the disorder with different genetic etiologies. We used the data provided to the participants in the Genetic Analysis Workshop 15 to evaluate and describe clinically based subgroups and their genetic associations with single-nucleotidepolymorphisms (SNPs) on chromosome 6, which harbors the HLA region. Detailed two- and three-SNP haplotype analyses were conducted in the HLA region. We used demographic, clinical self-report, and biomarker data from the entire sample (n = 8477) to identify and characterize the subgroups. We did not use the RA diagnosis itself in the identification of the subgroups. Nuclear families (715 families, 1998 individuals) were used to examine the genetic association with the HLA region. We found five distinct subgroups in the data. The first comprised unaffected family members. Cluster 2 was a mix of affected and unaffected in which patients endorsed symptoms not corroborated by physicians. Clusters 3 through 5 represented a severity continuum in RA. Cluster 5 was characterized by early onset severe disease. Cluster 2 showed no association on chromosome 6. Clusters 3 through 5 showed association with 17 SNPs on chromosome 6. In the HLA region, Cluster 3 showed single-, two-, and three-SNP association with the centromeric side of the region in an area of linkage disequilibrium. Cluster 5 showed both single- and two-SNP association with the telomeric side of the region in a second area of linkage disequilibrium. It will be important to replicate the subgroup structure and the association findings in an independent sample. PMID:18466517

The number of reports investigating disease susceptibility based on the carriage of low-penetrance, high-frequency single nucleotidepolymorphisms (SNPs) has increased in recent years. Evidence is accumulating defining specific individual variations in breast cancer susceptibility. Genetic variations of estradiol and xenobiotics metabolisms as well as genes involved in cell-cycle control have been described as significant contributors to breast cancer susceptibility, with variations depending on ethnic background and co-factors such as smoking and family history of breast cancer. In sum, the highest level of evidence to date linking SNPs and breast cancer comes from nested case-control studies within the prospective Nurses' Health Study. These data establish seven SNPs - hPRB +331G/A, AR CAG repeat, CYP19 (TTTA)10, CYP1A1 MspI, VDR FOK1, XRCC1 Arg194Trp and XRCC2 Arg188His - as small but significant risk factors for spontaneous, non-hereditary breast cancer. In addition, meta-analysis of data in the literature establishes the TGFBR1*6A, HRAS1, GSTP Ile105Val and GSTM1 SNPs as low-penetrance genetic risk factors of sporadic breast cancer. The clinical consequences of such a risk elevation may be detailed instruction of the patient as to general measures of breast cancer prevention such as a low-fat diet, optimization of body mass index, physical exercise, avoidance of alcohol and long-term hormone replacement therapy, and participation in a breast cancer screening program between the ages of 50 and 70 years. Specific surgical or drug interventions such as prophylactic mastectomy and oophorectomy or prophylactic intake of tamoxifen are not indicated based on SNP analysis at this time. PMID:16835078

Cerebrovascular disease is a leading cause of morbidity and mortality worldwide, which is influenced by genetic and environmental factors. The aim of the present study was to examine the association between single-nucleotidepolymorphisms (SNPs) in Notch3 exons 3–6 and lacunar infarction by comparing SNPs between control subjects and those with lacunar infarction. A single-center case-control study was conducted to investigate the association between Notch3 SNPs and risk of stroke. A total of 140 patients were included in the study, 30 of whom had no infarction (control) and 110 had lacunar infarction. Lacunar patients were divided into the ‘pure lacunar’ and ‘lacunar + leukoarasis’ groups based on brain imaging. All the patients were of Chinese Han ethnicity, and the male to female ratio was 84:56. Patient clinical histories included hypertension, diabetes mellitus (DM), hyperlipidemia, and heart disease were recorded. The Notch3 sequence was obtained from the National Centser for Biotechnology Information database. Notch3 was amplified by polymerase chain reaction from whole blood samples, and exons 3–6 were sequenced to identify SNPs. The result showed that there was no significant difference in the prevalence of hypertension, DM, hyperlipidemia, and heart disease between the control and lacunar infarction patients. Notabley, the age of the lacunar + leukoarasis patients was significantly higher than that of the control and pure lacunar patients (P<0.05). Eight SNPs were detected at low frequencies, and only rs3815388 and rs1043994 exhibited slightly higher frequencies. A χ2 test indicated that Notch3 SNPs, particularly rs1043994, were associated with lacunar infarction (P<0.05). In conclusion, the result of the present study have shown that Notch3 SNPs, particularly rs1043994, are associated with lacunar infarction. PMID:26889213

Purpose To determine whether single nucleotidepolymorphisms (SNPs) in genes associated with DNA repair, cell cycle, transforming growth factor beta, tumor necrosis factor and receptor, folic acid metabolism, and angiogenesis can significantly improve the fit of the Lyman-Kutcher-Burman (LKB) normal-tissue complication probability (NTCP) model of radiation pneumonitis (RP) risk among patients with non-small cell lung cancer (NSCLC). Methods and Materials Sixteen SNPs from 10 different genes (XRCC1, XRCC3, APEX1, MDM2, TGFβ, TNFα, TNFR, MTHFR, MTRR, and VEGF) were genotyped in 141 NSCLC patients treated with definitive radiotherapy, with or without chemotherapy. The LKB model was used to estimate the risk of severe (Grade ≥3) RP as a function of mean lung dose (MLD), with SNPs and patient smoking status incorporated into the model as dose-modifying factors. Multivariate (MV) analyses were performed by adding significant factors to the MLD model in a forward stepwise procedure, with significance assessed using the likelihood-ratio test. Bootstrap analyses were used to assess the reproducibility of results under variations in the data. Results Five SNPs were selected for inclusion in the multivariate NTCP model based on MLD alone. SNPs associated with an increased risk of severe RP were in genes for TGFβ, VEGF, TNFα, XRCC1 and APEX1. With smoking status included in the MV model, the SNPs significantly associated with increased risk of RP were in genes for TGFβ, VEGF, and XRCC3. Bootstrap analyses selected a median of 4 SNPs per model fit, with the 6 genes listed above selected most often. Conclusions This study provides evidence that SNPs can significantly improve the predictive ability of the Lyman MLD model. With a small number of SNPs, it was possible to distinguish cohorts with >50% risk versus <10% risk of RP when exposed to high MLDs. PMID:22541966

Background Castor bean (Ricinus communis) is an agricultural crop and garden ornamental that is widely cultivated and has been introduced worldwide. Understanding population structure and the distribution of castor bean cultivars has been challenging because of limited genetic variability. We analyzed the population genetics of R. communis in a worldwide collection of plants from germplasm and from naturalized populations in Florida, U.S. To assess genetic diversity we conducted survey sequencing of the genomes of seven diverse cultivars and compared the data to a reference genome assembly of a widespread cultivar (Hale). We determined the population genetic structure of 676 samples using single nucleotidepolymorphisms (SNPs) at 48 loci. Results Bayesian clustering indicated five main groups worldwide and a repeated pattern of mixed genotypes in most countries. High levels of population differentiation occurred between most populations but this structure was not geographically based. Most molecular variance occurred within populations (74%) followed by 22% among populations, and 4% among continents. Samples from naturalized populations in Florida indicated significant population structuring consistent with local demes. There was significant population differentiation for 56 of 78 comparisons in Florida (pairwise population ϕPT values, p < 0.01). Conclusion Low levels of genetic diversity and mixing of genotypes have led to minimal geographic structuring of castor bean populations worldwide. Relatively few lineages occur and these are widely distributed. Our approach of determining population genetic structure using SNPs from genome-wide comparisons constitutes a framework for high-throughput analyses of genetic diversity in plants, particularly in species with limited genetic diversity. PMID:20082707

Incorporation of genetic variants such as single nucleotidepolymorphisms (SNPs) into risk prediction models may account for a substantial fraction of attributable disease risk. Genetic data, from 2385 subjects recruited into the Liverpool Lung Project (LLP) between 2000 and 2008, consisting of 20 SNPs independently validated in a candidate-gene discovery study was used. Multifactor dimensionality reduction (MDR) and random forest (RF) were used to explore evidence of epistasis among 20 replicated SNPs. Multivariable logistic regression was used to identify similar risk predictors for lung cancer in the LLP risk model for the epidemiological model and extended model with SNPs. Both models were internally validated using the bootstrap method and model performance was assessed using area under the curve (AUC) and net reclassification improvement (NRI). Using MDR and RF, the overall best classifier of lung cancer status were SNPs rs1799732 (DRD2), rs5744256 (IL-18), rs2306022 (ITGA11) with training accuracy of 0.6592 and a testing accuracy of 0.6572 and a cross-validation consistency of 10/10 with permutation testing P<0.0001. The apparent AUC of the epidemiological model was 0.75 (95% CI 0.73–0.77). When epistatic data were incorporated in the extended model, the AUC increased to 0.81 (95% CI 0.79–0.83) which corresponds to 8% increase in AUC (DeLong's test P=2.2e-16); 17.5% by NRI. After correction for optimism, the AUC was 0.73 for the epidemiological model and 0.79 for the extended model. Our results showed modest improvement in lung cancer risk prediction when the SNP epistasis factor was added. PMID:27121382

Gene-to-gene variation in the frequency of single nucleotidepolymorphisms (SNPs) has been observed in humans, mice, rats, primates and pigs, but a relationship across species in this variation has not been described. Here, the frequency of porcine coding SNPs (cSNPs) identified by in silico methods, and the frequency of murine cSNPs, were compared with the frequency of human cSNPs across homologous genes. From 150,000 porcine expressed sequence tag (EST) sequences, a total of 452 SNP-containing sequence clusters were found, totalling 1394 putative SNPs. All the clustered porcine EST annotations and SNP data have been made publicly available at http://sputnik.btk.fi/project?name=swine. Human and murine cSNPs were identified from dbSNP and were characterized as either validated or total number of cSNPs (validated plus non-validated) for comparison purposes. The correlation between in silico pig cSNP and validated human cSNP densities was found to be 0.77 (p < 0.00001) for a set of 25 homologous genes, while a correlation of 0.48 (p < 0.0005) was found for a primarily random sample of 50 homologous human and mouse genes. This is the first evidence of conserved gene-to-gene variability in cSNP frequency across species and indicates that site-directed screening of porcine genes that are homologous to cSNP-rich human genes may rapidly advance cSNP discovery in pigs. PMID:16706918

Genetic variation arising from single nucleotidepolymorphisms (SNPs) is ubiquitously found among human populations. While disease-causing variants are known in some cases, identifying functional or causative variants for most human diseases remains a challenging task. Rare SNPs, rather than common ones, are thought to be more important in the pathology of most human diseases. We propose that rare SNPs should be divided into two categories dependent on whether the minor alleles are derived or ancestral. Derived alleles are less likely to have been purified by evolutionary processes and may be more likely to induce deleterious effects. We therefore hypothesized that the rare SNPs with derived minor alleles would be more important for human diseases and predicted that these variants would have larger functional or structural consequences relative to the rare variants for which the minor alleles are ancestral. We systematically investigated the consequences of the exonic SNPs on protein function, mRNA structure, and translation. We found that the functional and structural consequences are more significant for the rare exonic variants for which the minor alleles are derived. However, this pattern is reversed when the minor alleles are ancestral. Thus, the rare exonic SNPs with derived minor alleles are more likely to be deleterious. Age estimation of rare SNPs confirms that these potentially deleterious SNPs are recently evolved in the human population. These results have important implications for understanding the function of genetic variations in human exonic regions and for prioritizing functional SNPs in genome-wide association studies of human diseases. PMID:26454016

The purpose of this study was to characterize genetic architecture of behavior patterns in Sapsaree dogs. The breed population (n = 8,256) has been constructed since 1990 over 12 generations and managed at the Sapsaree Breeding Research Institute, Gyeongsan, Korea. Seven behavioral traits were investigated for 882 individuals. The traits were classified as a quantitative or a categorical group, and heritabilities (h2) and variance components were estimated under the Animal model using ASREML 2.0 software program. In general, the h2 estimates of the traits ranged between 0.00 and 0.16. Strong genetic (rG) and phenotypic (rP) correlations were observed between nerve stability, affability and adaptability, i.e. 0.9 to 0.94 and 0.46 to 0.68, respectively. To detect significant single nucleotidepolymorphism (SNP) for the behavioral traits, a total of 134 and 60 samples were genotyped using the Illumina 22K CanineSNP20 and 170K CanineHD bead chips, respectively. Two datasets comprising 60 (Sap60) and 183 (Sap183) samples were analyzed, respectively, of which the latter was based on the SNPs that were embedded on both the 22K and 170K chips. To perform genome-wide association analysis, each SNP was considered with the residuals of each phenotype that were adjusted for sex and year of birth as fixed effects. A least squares based single marker regression analysis was followed by a stepwise regression procedure for the significant SNPs (p<0.01), to determine a best set of SNPs for each trait. A total of 41 SNPs were detected with the Sap183 samples for the behavior traits. The significant SNPs need to be verified using other samples, so as to be utilized to improve behavior traits via marker-assisted selection in the Sapsaree population. PMID:26104397

Ficolin-2 (FCN2) is an innate immune pattern recognition molecule that can activate the complement pathway, opsonophagocytosis, and elimination of the pathogens. The present study aimed to investigate the association of the FCN2 gene single nucleotidepolymorphisms (SNPs) with susceptibility to pulmonary tuberculosis (TB). A total of seven SNPs in exon 8 (+6359 C>T and +6424 G>T) and in the promoter region (-986 G>A, -602 G>A, -557 A>G, -64 A>C and -4 A>G) of the FCN2 gene were genotyped using the PCR amplification and DNA sequencing methods in the healthy controls group (n = 254) and the pulmonary TB group (n = 282). The correlation between SNPs and pulmonary TB was analyzed using the logistic regression method. The results showed that there were no significant differences in the distribution of allelic frequencies of seven SNPs between the pulmonary TB group and the healthy controls group. However, the frequency of the variant homozygous genotype (P = 0.037, -557 A>G; P = 0.038, -64 A>C; P = 0.024, +6424 G>T) in the TB group was significantly lower than the control group. After adjustment for age and gender, these variant homozygous genotypes were found to be recessive models in association with pulmonary TB. In addition, -64 A>C (P = 0.047) and +6424 G>T (P = 0.03) were found to be codominant models in association with pulmonary TB. There was strong linkage disequilibrium (r2 > 0.80, P < 0.0001) between 7 SNPs except the -602 G>A site. Therefore, -557 A>G, -64 A>C and +6424 G>T SNPs of the FCN2 gene were correlated with pulmonary TB, and may be protective factors for TB. This study provides a novel idea for the prevention and control of TB transmission from a genetics perspective. PMID:26379154

Despite decades of eradication efforts, malaria remains a global burden. Recent renewed interest in regional elimination and global eradication has been accompanied by increased genomic information about Plasmodium parasite species responsible for malaria, including characteristics of geographical populations as well as variations associated with reduced susceptibility to anti-malarial drugs. One common genetic variation, single-nucleotidepolymorphisms (SNPs), offers attractive targets for parasite genotyping. These markers are useful not only for tracking drug resistance markers but also for tracking parasite populations using markers not under drug or other selective pressures. SNP genotyping methods offer the ability to track drug resistance as well as to fingerprint individual parasites for population surveillance, particularly in response to malaria control efforts in regions nearing elimination status. While informative SNPs have been identified that are agnostic to specific genotyping technologies, high-resolution melting (HRM) analysis is particularly suited to field-based studies. Compared to standard fluorescent-probe based methods that require individual SNPs in a single labeled probe and offer at best 10% sensitivity to detect SNPs in samples that contain multiple genomes (polygenomic), HRM offers 2-5% sensitivity. Modifications to HRM, such as blocked probes and asymmetric primer concentrations as well as optimization of amplification annealing temperatures to bias PCR towards amplification of the minor allele, further increase the sensitivity of HRM. While the sensitivity improvement depends on the specific assay, we have increased detection sensitivities to less than 1% of the minor allele. In regions approaching malaria eradication, early detection of emerging or imported drug resistance is essential for prompt response. Similarly, the ability to detect polygenomic infections and differentiate imported parasite types from cryptic local reservoirs

Despite decades of eradication efforts, malaria remains a global burden. Recent renewed interest in regional elimination and global eradication has been accompanied by increased genomic information about Plasmodium parasite species responsible for malaria, including characteristics of geographical populations as well as variations associated with reduced susceptibility to anti-malarial drugs. One common genetic variation, single-nucleotidepolymorphisms (SNPs), offers attractive targets for parasite genotyping. These markers are useful not only for tracking drug resistance markers but also for tracking parasite populations using markers not under drug or other selective pressures. SNP genotyping methods offer the ability to track drug resistance as well as to fingerprint individual parasites for population surveillance, particularly in response to malaria control efforts in regions nearing elimination status. While informative SNPs have been identified that are agnostic to specific genotyping technologies, high-resolution melting (HRM) analysis is particularly suited to field-based studies. Compared to standard fluorescent-probe based methods that require individual SNPs in a single labeled probe and offer at best 10% sensitivity to detect SNPs in samples that contain multiple genomes (polygenomic), HRM offers 2-5% sensitivity. Modifications to HRM, such as blocked probes and asymmetric primer concentrations as well as optimization of amplification annealing temperatures to bias PCR towards amplification of the minor allele, further increase the sensitivity of HRM. While the sensitivity improvement depends on the specific assay, we have increased detection sensitivities to less than 1% of the minor allele. In regions approaching malaria eradication, early detection of emerging or imported drug resistance is essential for prompt response. Similarly, the ability to detect polygenomic infections and differentiate imported parasite types from cryptic local reservoirs

Keloids are abnormally raised fibroproliferative lesions that usually occur following cutaneous traumas. Recently, a large-scale genome-wide association study (GWAS) has identified multiple single nucleotidepolymorphisms (SNPs) in three genetic loci that are associated with keloids in Japanese population. Subsequently, two reported loci 1q41 (rs873549 and rs1442440) and 15q21.3 (rs2271289) for keloids were confirmed in selected Chinese population. The association of these SNPs with clinical features of keloids, has not yet been studied. To explore the role of these SNPs in the pathogenesis of keloids, we performed a case-controlled study in another independent Chinese Han population to analyze the correlation between 4 SNPs (rs873549, rs2118610, rs1511412, rs2271289) and keloids phenotypes. 309 keloids patients and 1080 control subjects were included. The results showed that, in the dominant mode of inheritance, the minor allele T of SNP rs2271289 had significantly higher odd ratios (ORs) in the severe keloid group compared with both the controls and the mild keloid group. The ORs were maintained after Bonferroni’s correction (OR: 4.09, 95% CI: 1.78-9.37, P-value 3.25E-04). The ratio of the severe: mild OR for rs2271289 (dominant model) is (4.73/1.84=2.57). Similar associations in SNP rs2271289 were seen for groups with no family history and multiplesite compared with the control groups. No associations between keloid number, family history or severity relative to the controls were observed for the other three SNPs. Our data support that rs2271289 is strongly associated with severe keloids and might contribute to the complexity of clinical features of keloids. PMID:27158346

Incorporating historical tissues into the study of ecological, conservation and management questions can broaden the scope of population genetic research by enhancing our understanding of evolutionary processes and anthropogenic influences on natural populations. Genotyping historical and low-quality samples has been plagued by challenges associated with low amounts of template DNA and the potential for pre-existing DNA contamination among samples. We describe a two-step process designed to (i) accurately genotype large numbers of historical low-quality scale samples in a high-throughput format and (ii) screen samples for pre-existing DNA contamination. First, we describe how an efficient multiplex preamplification PCR of 45 single nucleotidepolymorphisms (SNPs) can generate highly accurate genotypes with low failure and error rates in subsequent SNP genotyping reactions of individual historical scales from sockeye salmon (Oncorhynchus nerka). Second, we demonstrate how the method can be modified for the amplification of microsatellite loci to detect pre-existing DNA contamination. A total of 760 individual historical scale and 182 contemporary fin clip samples were genotyped and screened for contamination. Genotyping failure and error rates were exceedingly low and similar for both historical and contemporary samples. Pre-existing contamination in 21% of the historical samples was successfully identified by screening the amplified microsatellite loci. The advantages of automation, low failure and error rates, and ability to multiplex both the preamplification and subsequent genotyping reactions combine to make the protocol ideally suited for efficiently genotyping large numbers of potentially contaminated low-quality sources of DNA. PMID:21429180

Glioma is a complex disease that is unlikely to result from the effect of a single gene. Genetic analysis at the pathway level involving multiple genes may be more likely to capture gene-disease associations than analyzing genes one at a time. The current pilot study included 112 Caucasians with glioblastoma multiforme and 112 Caucasian healthy controls frequency matched to cases by age and gender. Subjects were genotyped using a commercially available (ParAllele/Affymetrix) assay panel of 10,177 nonsynonymous coding single-nucleotidepolymorphisms (SNP) spanning the genome known at the time the panel was constructed. For this analysis, we selected 10 pathways potentially involved in gliomagenesis that had SNPs represented on the panel. We performed random forests (RF) analyses of SNPs within each pathway group and logistic regression to assess interaction among genes in the one pathway for which the RF prediction error was better than chance and the permutation P < 0.10. Only the DNA repair pathway had a better than chance classification of case-control status with a prediction error of 45.5% and P = 0.09. Three SNPs (rs1047840 of EXO1, rs12450550 of EME1, and rs799917 of BRCA1) of the DNA repair pathway were identified as promising candidates for further replication. In addition, statistically significant interactions (P < 0.05) between rs1047840 of EXO1 and rs799917 or rs1799966 of BRCA1 were observed. Despite less than complete inclusion of genes and SNPs relevant to glioma and a small sample size, RF analysis identified one important biological pathway and several SNPs potentially associated with the development of glioblastoma. PMID:18559551

Genetic determinants appear to play a role in susceptibility to chronic diarrhea, but the genetic abnormalities involved have only been identified in a few conditions. The Na+/H+ exchanger 3 (NHE3) accounts for a large fraction of physiologic intestinal Na+ absorption. It is highly regulated through effects on its intracellular COOH-terminal regulatory domain. The impact of genetic variation in the NHE3 gene, such as single nucleotidepolymorphisms (SNPs), on transporter activity remains unexplored. From a total of 458 SNPs identified in the entire NHE3 gene, we identified three nonsynonymous mutations (R474Q, V567M, and R799C), which were all in the protein's intracellular COOH-terminal domain. Here we evaluated whether these SNPs affect NHE3 activity by expressing them in a mammalian cell line that is null for all plasma membrane NHEs. These variants significantly reduced basal NHE3 transporter activity through a reduction in intrinsic NHE3 function in variant R474Q, abnormal trafficking in variant V567M, or defects in both intrinsic NHE3 function and trafficking in variant R799C. In addition, variants NHE3 R474Q and R799C failed to respond to acute dexamethasone stimulation, suggesting cells with these mutant proteins might be defective in NHE3 function during postprandial stimulation and perhaps under stressful conditions. Finally, variant R474Q was shown to exhibit an aberrant interaction with calcineurin B homologous protein (CHP), an NHE3 regulatory protein required for basal NHE3 activity. Taken together, these results demonstrate decreased transport activity in three SNPs of NHE3 and provide mechanistic insight into how these SNPs impact NHE3 function. PMID:25715704

Short tandem repeats (STRs) are conventional genetic markers typically used for paternity and kinship testing. As supplementary markers of STRs, single nucleotidepolymorphisms (SNPs) have less discrimination power but broader applicability to degraded samples. The rapid improvement of next-generation sequencing (NGS) and multiplex amplification technologies also make it possible now to simultaneously identify dozens or even hundreds of SNP loci in a single pool. However, few studies have been endeavored to kinship testing based on SNP loci. In this study, we genotyped 90 autosomal human identity SNP loci with NGS, and investigated their testing efficacies based on the likelihood ratio model in eight pedigree scenarios involving paternity, half/full-sibling, uncle/nephew, and first-cousin relationships. We found that these SNPs might be sufficient to discriminate paternity and full-sibling, but impractical for more distant relatives such as uncle and cousin. Furthermore, we conducted an in silico study to obtain the theoretical tendency of how testing efficacy varied with increasing number of SNP loci. For each testing battery in a given pedigree scenario, we obtained distributions of logarithmic likelihood ratio for both simulated relatives and unrelated controls. The proportion of the overlapping area between the two distributions was defined as a false testing level (FTL) to evaluate the testing efficacy. We estimated that 85, 127, 491, and 1,858 putative SNP loci were required to discriminate paternity, full-sibling, half-sibling/uncle-nephew, and first-cousin (FTL, 0.1%), respectively. To test a half-sibling or nephew, an additional uncle relative could be included to decrease the required number of putative SNP loci to ∼320 (FTL, 0.1%). As a systematic computation of paternity and kinship testing based only on SNPs, our results could be informative for further studies and applications on paternity and kinship testing using SNP loci. PMID:26952733

Summary Currently, single-nucleotidepolymorphisms (SNPs) with minor allele frequency (MAF) of >5% are preferentially used in case-control association studies of common human diseases. Recent technological developments enable inexpensive and accurate genotyping of a large number of SNPs in thousands of cases and controls, which can provide adequate statistical power to analyze SNPs with MAF <5%. Our purpose was to determine whether evaluating rare SNPs in case-control association studies could help identify causal SNPs for common diseases. We suggest that slightly deleterious SNPs (sdSNPs) subjected to weak purifying selection are major players in genetic control of susceptibility to common diseases. We compared the distribution of MAFs of synonymous SNPs with that of nonsynonymous SNPs (1) predicted to be benign, (2) predicted to be possibly damaging, and (3) predicted to be probably damaging by PolyPhen. Our sources of data were the International HapMap Project, ENCODE, and the SeattleSNPs project. We found that the MAF distribution of possibly and probably damaging SNPs was shifted toward rare SNPs compared with the MAF distribution of benign and synonymous SNPs that are not likely to be functional. We also found an inverse relationship between MAF and the proportion of nsSNPs predicted to be protein disturbing. On the basis of this relationship, we estimated the joint probability that a SNP is functional and would be detected as significant in a case-control study. Our analysis suggests that including rare SNPs in genotyping platforms will advance identification of causal SNPs in case-control association studies, particularly as sample sizes increase. PMID:18179889

The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify species-specific diagnostic single-nucleotidepolymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N=159) and from the neighboring Faroe Islands (N=29) were genotyped, along with 94 larvae (49 European and 45 American eel) collected in the Sargasso Sea. Our SNP survey showed that the majority of Icelandic eels are pure European eels but there is also an important contribution of individuals of admixed ancestry (10.7%). Although most of the hybrids were identified as F1 hybrids from European eel female × American eel male crosses, backcrosses were also detected, including a first-generation backcross (F1 hybrid × pure European eel) and three individuals identified as second-generation backcrosses originating from American eel × F1 hybrid backcrosses interbreeding with pure European eels. In comparison, no hybrids were observed in the Faroe Islands, the closest bodies of land to Iceland. It is possible that hybrids show an intermediate migratory behaviour between the two parental species that ultimately brings hybrid larvae to the shores of Iceland, situated roughly halfway between the Sargasso Sea and Europe. Only two hybrids were observed among Sargasso Sea larvae, both backcrosses, but no F1 hybrids, that points to temporal variation in the occurrence of hybridization. PMID:24424165

Purpose: To determine whether single-nucleotidepolymorphisms (SNPs) in genes associated with DNA repair, cell cycle, transforming growth factor-{beta}, tumor necrosis factor and receptor, folic acid metabolism, and angiogenesis can significantly improve the fit of the Lyman-Kutcher-Burman (LKB) normal-tissue complication probability (NTCP) model of radiation pneumonitis (RP) risk among patients with non-small cell lung cancer (NSCLC). Methods and Materials: Sixteen SNPs from 10 different genes (XRCC1, XRCC3, APEX1, MDM2, TGF{beta}, TNF{alpha}, TNFR, MTHFR, MTRR, and VEGF) were genotyped in 141 NSCLC patients treated with definitive radiation therapy, with or without chemotherapy. The LKB model was used to estimate the risk of severe (grade {>=}3) RP as a function of mean lung dose (MLD), with SNPs and patient smoking status incorporated into the model as dose-modifying factors. Multivariate analyses were performed by adding significant factors to the MLD model in a forward stepwise procedure, with significance assessed using the likelihood-ratio test. Bootstrap analyses were used to assess the reproducibility of results under variations in the data. Results: Five SNPs were selected for inclusion in the multivariate NTCP model based on MLD alone. SNPs associated with an increased risk of severe RP were in genes for TGF{beta}, VEGF, TNF{alpha}, XRCC1 and APEX1. With smoking status included in the multivariate model, the SNPs significantly associated with increased risk of RP were in genes for TGF{beta}, VEGF, and XRCC3. Bootstrap analyses selected a median of 4 SNPs per model fit, with the 6 genes listed above selected most often. Conclusions: This study provides evidence that SNPs can significantly improve the predictive ability of the Lyman MLD model. With a small number of SNPs, it was possible to distinguish cohorts with >50% risk vs <10% risk of RP when they were exposed to high MLDs.

Purpose There is accumulating evidence that oxidative stress is an important contributor to carcinogenesis. We hypothesized that genetic variation in genes involved in maintaining antioxidant/oxidant balance would be associated with overall oxidative stress. Methods We examined associations between single nucleotidepolymorphisms (SNPs) in MnSOD, GSTP1, GSTM1, GPX1, GPX3, and CAT genes and thiobarbituric acid-reactive substances (TBARS), a blood biomarker of oxidative damage, in healthy white women randomly selected from Western New York (n = 1402). We used general linear models to calculate age-adjusted geometric means of TBARS across the variants. We also examined the associations within strata of menopausal status. Results For MnSOD, being heterozygous was associated with lower geometric means of TBARS (less oxidative stress), 1.28 mg/dL, compared to homozygous T-allele or homozygous C-allele,1.35 mg/dL, and 1.31 mg/dL correspondingly (p for trend = 0.01). This difference remained among postmenopausal women, 1.40 mg/dL for TT, 1.32 mg/dL for TC, and 1.34mg/dL for CC (p for trend 0.015); it was attenuated among premenopausal women. SNPs in the other genes examined (GSTP1, GSTM1, GPX1, GPX3, and CAT) were not associated with TBARS. Conclusions Our findings suggest that genetic variation in MnSOD gene may be associated with oxidative status, particularly among postmenopausal women. PMID:27271305

Polymerase-free and label-free strategies for DNA detection have shown excellent sensitivity and specificity in various biological samples. Herein, we propose a method for single nucleotidepolymorphism (SNP) detection by using self-assembled DNA concatemers. Capture probes, bound to magnetic beads, can joint mediator probes by T4 DNA ligase in the presence of target DNA that is complementary to the capture probe and mediator probe. The mediator probes trigger self-assembly of two auxiliary probes on magnetic beads to form DNA concatemers. Separated by a magnetic rack, the double-stranded concatemers on beads can recruit a great amount of SYBR Green I and eventually result in amplified fluorescent signals. In comparison with reported methods for SNP detection, the concatemer-based approach has significant advantages of low background, simplicity, and ultrasensitivity, making it as a convenient platform for clinical applications. As a proof of concept, BRAF(T1799A) oncogene mutation, a SNP involved in diverse human cancers, was used as a model target. The developed approach using a fluorescent intercalator can detect as low as 0.1 fM target BRAF(T1799A) DNA, which is better than those previously published methods for SNP detection. This method is robust and can be used directly to measure the BRAF(T1799A) DNA in complex human serum with excellent recovery (94-103%). It is expected that this assay principle can be directed toward other SNP genes by simply changing the mediator probe and auxiliary probes. PMID:24267087

Aldehyde oxidase (AOX1) is an enzyme with broad substrate specificity, catalyzing the oxidation of a wide range of endogenous and exogenous aldehydes as well as N-heterocyclic aromatic compounds. In humans, the enzyme's role in phase I drug metabolism has been established and its importance is now emerging. However, the true physiologic function of AOX1 in mammals is still unknown. Further, numerous single-nucleotidepolymorphisms (SNPs) have been identified in human AOX1. SNPs are a major source of interindividual variability in the human population, and SNP-based amino acid exchanges in AOX1 reportedly modulate the catalytic function of the enzyme in either a positive or negative fashion. For the reliable analysis of the effect of amino acid exchanges in human proteins, the existence of reproducible expression systems for the production of active protein in ample amounts for kinetic, spectroscopic, and crystallographic studies is required. In our study we report an optimized expression system for hAOX1 in Escherichia coli using a codon-optimized construct. The codon-optimization resulted in an up to 15-fold increase of protein production and a simplified purification procedure. The optimized expression system was used to study three SNPs that result in amino acid changes C44W, G1269R, and S1271L. In addition, the crystal structure of the S1271L SNP was solved. We demonstrate that the recombinant enzyme can be used for future studies to exploit the role of AOX in drug metabolism, and for the identification and synthesis of new drugs targeting AOX when combined with crystallographic and modeling studies. PMID:26842593

Accurate pedigrees are essential to optimize genetic improvement and conservation of animal genetic resources. In goats, the use of mating groups and kidding management procedures hamper the identification of parentage. Small panels of single nucleotidepolymorphisms (SNP) have been proposed in other species to substitute microsatellites for parentage assessment. Using data from the current GoatSNP50 chip, we developed a new 3-step procedure to identify a low-density SNP panel for highly accurate parentage assessment. Methodologies for SNP selection used in other species are less suitable in the goat because of uncertainties in the genome assembly. The procedure developed in this study is based on parent-offspring identification and on estimation of Mendelian errors, followed by canonical discriminant analysis identification and stepwise regression reduction. Starting from a reference sample of 109 Alpine goats with known pedigree relationships, we first identified a panel of 200 SNP that was further reduced to 2 final panels of 130 and 114 SNP with random coincidental match inclusion of 1.51×10(-57) and 2.94×10(-34), respectively. In our reference data set, all panels correctly identified all parent-offspring combinations, revealing a 40% pedigree error rate in the information provided by breeders. All reference trios were confirmed by official tests based on microsatellites. Panels were also tested on Saanen and Teramana breeds. Although the testing on a larger set of breeds in the reference population is still needed to validate these results, our findings suggest that our procedure could identify SNP panels for accurate parentage assessment in goats or in other species with unreliable marker positioning. PMID:26971153

Interferon (IFN) signaling has been suggested to play an important role in colorectal carcinogenesis. Our study aimed to examine potentially functional genetic variants in interferon regulatory factor 3 (IRF3), IRF5, IRF7, type I and type II IFN and their receptor genes with respect to colorectal cancer (CRC) risk and clinical outcome. Altogether 74 single nucleotidepolymorphisms (SNPs) were covered by the 34 SNPs genotyped in a hospital-based case-control study of 1327 CRC cases and 758 healthy controls from the Czech Republic. We also analyzed these SNPs in relation to overall survival and event-free survival in a subgroup of 483 patients. Seven SNPs in IFNA1, IFNA13, IFNA21, IFNK, IFNAR1 and IFNGR1 were associated with CRC risk. After multiple testing correction, the associations with the SNPs rs2856968 (IFNAR1) and rs2234711 (IFNGR1) remained formally significant (P = 0.0015 and P<0.0001, respectively). Multivariable survival analyses showed that the SNP rs6475526 (IFNA7/IFNA14) was associated with overall survival of the patients (P = 0.041 and event-free survival among patients without distant metastasis at the time of diagnosis, P = 0.034). The hazard ratios (HRs) for rs6475526 remained statistically significant even after adjustment for age, gender, grade and stage (P = 0.029 and P = 0.036, respectively), suggesting that rs6475526 is an independent prognostic marker for CRC. Our data suggest that genetic variation in the IFN signaling pathway genes may play a role in the etiology and survival of CRC and further studies are warranted. PMID:25350395

Likelihood-based parentage inference depends on the distribution of a likelihood-ratio statistic, which, in most cases of interest, cannot be exactly determined, but only approximated by Monte Carlo simulation. We provide importance-sampling algorithms for efficiently approximating very small tail probabilities in the distribution of the likelihood-ratio statistic. These importance-sampling methods allow the estimation of small false-positive rates and hence permit likelihood-based inference of parentage in large studies involving a great number of potential parents and many potential offspring. We investigate the performance of these importance-sampling algorithms in the context of parentage inference using single-nucleotidepolymorphism (SNP) data and find that they may accelerate the computation of tail probabilities >1 millionfold. We subsequently use the importance-sampling algorithms to calculate the power available with SNPs for large-scale parentage studies, paying particular attention to the effect of genotyping errors and the occurrence of related individuals among the members of the putative mother–father–offspring trios. These simulations show that 60–100 SNPs may allow accurate pedigree reconstruction, even in situations involving thousands of potential mothers, fathers, and offspring. In addition, we compare the power of exclusion-based parentage inference to that of the likelihood-based method. Likelihood-based inference is much more powerful under many conditions; exclusion-based inference would require 40% more SNP loci to achieve the same accuracy as the likelihood-based approach in one common scenario. Our results demonstrate that SNPs are a powerful tool for parentage inference in large managed and/or natural populations. PMID:16387880

Background To better understand the genetic determination of udder health, we performed a genome-wide association study (GWAS) on a population of 2354 German Holstein bulls for which daughter yield deviations (DYD) for somatic cell score (SCS) were available. For this study, we used genetic information of 44 576 informative single nucleotidepolymorphisms (SNPs) and 11 725 inferred haplotype blocks. Results When accounting for the sub-structure of the analyzed population, 16 SNPs and 10 haplotypes in six genomic regions were significant at the Bonferroni threshold of P ≤ 1.14 × 10-6. The size of the identified regions ranged from 0.05 to 5.62 Mb. Genomic regions on chromosomes 5, 6, 18 and 19 coincided with known QTL affecting SCS, while additional genomic regions were found on chromosomes 13 and X. Of particular interest is the region on chromosome 6 between 85 and 88 Mb, where QTL for mastitis traits and significant SNPs for SCS in different Holstein populations coincide with our results. In all identified regions, except for the region on chromosome X, significant SNPs were present in significant haplotypes. The minor alleles of identified SNPs on chromosomes 18 and 19, and the major alleles of SNPs on chromosomes 6 and X were favorable for a lower SCS. Differences in somatic cell count (SCC) between alternative SNP alleles reached 14 000 cells/mL. Conclusions The results support the polygenic nature of the genetic determination of SCS, confirm the importance of previously reported QTL, and provide evidence for the segregation of additional QTL for SCS in Holstein cattle. The small size of the regions identified here will facilitate the search for causal genetic variations that affect gene functions. PMID:24898131

Background & Aims RAC1 is a GTPase that has an evolutionarily conserved role in coordinating immune defenses, from plants to mammals. Chronic inflammatory bowel diseases (IBD) are associated with dysregulation of immune defenses. We studied the role of RAC1 in IBD using human genetic and functional studies and animal models of colitis. Methods We used a candidate gene approach to HapMap-Tag single nucleotidepolymorphisms (SNPs) in a discovery cohort; findings were confirmed in 2 additional cohorts. RAC1 mRNA expression was examined from peripheral blood cells of patients. Colitis was induced in mice with conditional disruption of Rac1 in phagocytes by administration of dextran sulphate sodium (DSS). Results We observed a genetic association between RAC1 with ulcerative colitis (UC) in a discovery cohort, 2 independent replication cohorts, and in combined analysis for the SNPs rs10951982 (Pcombined UC = 3.3 × 10–8, odds ratio [OR]=1.43 [1.26–1.63]) and rs4720672 (Pcombined UC=4.7 × 10–6, OR=1.36 [1.19–1.58]). Patients with IBD who had the rs10951982 risk allele had increased expression of RAC1, compared to those without this allele. Conditional disruption of Rac1 in macrophage and neutrophils of mice protected them against DSS-induced colitis. Conclusion Studies of human tissue samples and knockout mice demonstrated a role for the GTPase RAC1 in the development of UC; increased expression of RAC1 was associated with susceptibility to colitis. PMID:21684284

The α7nicotinic receptor (nAChR) is a major subtype of the nAChRs in the central nervous system, and the receptor plays an important role in brain function. In the dbSNP database, there are 55 single nucleotidepolymorphisms (SNPs) that cause missense mutations of the human α7nAChR in the coding region. In this study, we tested the impact of 14 SNPs that cause missense mutations in the agonist binding site or the coupling region between binding site and channel gate on the receptor function. The wild type or mutant receptors were expressed or co-expressed in Xenopus oocytes, and the agonist-induced currents were tested using two-electrode voltage clamp. Our results demonstrated that 6 mutants were nonfunctional, 4 mutants had reduced current expression, and 1 mutants altered ACh and nicotine efficacy in the opposite direction, and one additional mutant had slightly reduced agonist sensitivity. Interestingly, the function of most of these nonfunctional mutants could be rescued by α7nAChR positive allosteric modulator PNU-120596 and agonist-PAM 4BP-TQS. Finally, when coexpressed with the wild type, the nonfunctional mutants could also influence the receptor function. These changes of the receptor properties by the mutations could potentially have an impact on the physiological function of the α7nAChR-mediated cholinergic synaptic transmission and anti-inflammatory effects in the human SNP carriers. Rescuing the nonfunctional mutants could provide a novel way to treat the related disorders. PMID:26340537

Litchi is an important fruit tree in tropical and subtropical areas of the world. However, there is widespread confusion regarding litchi cultivar nomenclature and detailed information of genetic relationships among litchi germplasm is unclear. In the present study, the potential of single nucleotidepolymorphism (SNP) for the identification of 96 representative litchi accessions and their genetic relationships in China was evaluated using 155 SNPs that were evenly spaced across litchi genome. Ninety SNPs with minor allele frequencies above 0.05 and a good genotyping success rate were used for further analysis. A relatively high level of genetic variation was observed among litchi accessions, as quantified by the expected heterozygosity (He = 0.305). The SNP based multilocus matching identified two synonymous groups, ‘Heiye’ and ‘Wuye’, and ‘Chengtuo’ and ‘Baitangli 1’. A subset of 14 SNPs was sufficient to distinguish all the non-redundant litchi genotypes, and these SNPs were proven to be highly stable by repeated analyses of a selected group of cultivars. Unweighted pair-group method of arithmetic averages (UPGMA) cluster analysis divided the litchi accessions analyzed into four main groups, which corresponded to the traits of extremely early-maturing, early-maturing, middle-maturing, and late-maturing, indicating that the fruit maturation period should be considered as the primary criterion for litchi taxonomy. Two subpopulations were detected among litchi accessions by STRUCTURE analysis, and accessions with extremely early- and late-maturing traits showed membership coefficients above 0.99 for Cluster 1 and Cluster 2, respectively. Accessions with early- and middle-maturing traits were identified as admixture forms with varying levels of membership shared between the two clusters, indicating their hybrid origin during litchi domestication. The results of this study will benefit litchi germplasm conservation programs and facilitate maximum

Context: Cholecystokinin A receptor (CCK-AR) gene polymorphism is being increasingly reported in schizophrenia. It varies among different population groups but is associated with several complications of schizophrenia. Aims: The present study was undertaken to assess whether the CCK-AR polymorphism is stabilized and is more consistently associated with schizophrenia in an Eastern Indian sub-population. Settings and Design: It was carried out as a cross-sectional, observational, hospital-based study on 95 schizophrenia patients and 138 control subjects selected by the method of convenience. Materials and Methods: Single-nucleotidepolymorphisms located in the regulatory region of the CCK-AR gene were assessed by restriction fragment length polymorphism (RFLP) in the polymerase chain reaction (PCR) amplified product of CCK-AR gene in study subjects. RFLP was done by the digestion of the PCR product by the restriction enzyme Pst-1 followed by gel electrophoresis. Statistical Analysis: Assessment of the stability of C/T polymorphism in the study population was done by applying Hardy–Weinberg equilibrium rule. The significance of difference in the allelic distribution between case and controls was analyzed by Chi-square (χ2) test and odds ratio (OR) analysis. Result: CCK-R polymorphism was in Hardy–Weinberg equilibrium in both groups. Distribution of the C allele of this gene was significantly higher in schizophrenia patients (χ2 = 4.35, OR = 1.51; confidence interval at 95% =1.04–2.20). Conclusion: C/T polymorphism of the CCK-R gene is a stable polymorphism in our study population. Moreover, the C allele is significantly more abundant in schizophrenia patients imparting them a greater risk of development of complications like auditory hallucination. PMID:26600580

Single-nucleotidepolymorphisms (SNPs) are the most common genetic markers in Theobroma cacao, occurring approximately once in every 200 nucleotides. SNPs, like microsatellites, are co-dominant and PCR-based, but they have several advantages over microsatellites. They are unambiguous, so that a SN...

The most common type of genetic disease-associated mutation is the single nucleotidepolymorphism (SNP). Because most genetic diseases can be caused by multiple SNPs in the same gene, effective routine diagnosis of complex genetic diseases is dependent on a simple and reliable method of interrogating SNP sites. Molecular Tool`s solid phase assay capable of direct genotyping (single base sequencing) of SNP sites, Genetic Bit Analysis (GBA), involves hybridization-capture of a single-stranded PCR product to a sequence-specific, microtiter plate-bound oligonucleotide primer. The captured PCR product then acts as template for single-base extension of the capture primer across the polymorphic site, enabling direct determination of the base composition of the polymorphism through a simple colormetric assay. Genotyping in a high volume, semi-automated, processing system with a current capacity of 100 SNP interrogations per technician per day enables the screening of candidate mutations rapidly and cost-effectively, critically important to comprehensive genetic diagnosis. Using this gel-free technology, we have developed prototype diagnostic tests for CFTR and ApoE polymorphisms which enable direct sequencing of the polymorphic base at each site of interest. Routine clinical diagnosis of genetically complex diseases such as cystic fibrosis is dependent on this combination of robust biochemistry and simple format. Additionally, the ability to transfer the format and biochemistry to any disease gene of interest enables the broad application of this technology to clinical diagnostics, especially for genetically complex diseases.

Recent studies have identified more than 160 inflammatory bowel disease susceptibility loci and provided evidence for genetic heritability in disease pathogenesis. Here we describe a case of a 47-year-old White woman suffering from Crohn's disease (CD), who had four children, two with CD and two with a factor V Leiden variation. We analysed the presence of single nucleotidepolymorphisms in several CD susceptibility genes. SNP analysis was carried out using commercially available assays. The female CD patient had a positive inflammatory bowel disease family history. All of the patients had a mild disease course, without fistulae or symptomatic stenosis. The patient was heterozygous for risk variants of the genes encoding nucleotide oligomerization domain 2 (NOD2) and Toll-like receptor 5 (TLR5) and a homozygous carrier of both of the identified protein tyrosine phosphatase nonreceptor type 2 (PTPN2) risk alleles. The CD-affected daughter carried heterozygous risk alleles of the genes encoding TLR5, NOD2 and PTPN2. The son, with the earliest onset of disease in the family at the age of 12 years, was heterozygous for risk alleles of autophagy 16 like 1 (ATG16L1), TLR5, NOD2 and PTPN2. This study reports an interesting pattern of CD-associated single nucleotidepolymorphisms in a family with CD. This report clearly supports the observation that genetic variations, especially in genes associated with the innate immune system, contribute to disease onset. PMID:24901824

Premise of the Study: Studies of the geographic patterns of genetic variation can give important insights into the past population structure of species. Our study species, Taxodium distichum L. (bald-cypress), prefers riparian and wetland habitats and is widely distributed in southeastern North America and Mexico. We compared the genetic variation of T. distichum with that of its close relative, Cryptomeria japonica, which is endemic to Japan. Methods: Nucleotidepolymorphisms of T. distichum in the lower Mississippi River alluvial valley, USA, were examined at 10 nuclear loci. Key Results: The average nucleotide diversity at silent sites, 7sil, across the 10 loci in T. distichum was higher than that of C. japonica (7sil = 0.00732 and 0.00322, respectively). In T. distichum, Tajima's D values were each negative at 9 out of 10 loci, which suggests a recent population expansion. Maximum-likelihood and Bayesian estimations of the exponential population growth rate (g) of T. distichum populations indicated that this species had expanded approximately at the rate of 1.7 - 1.0 10 -6 per year in the past. Conclusions: Taxodium distichum had signifi cantly higher nucleotide variation than C. japonica, and its patterns of polymorphism contrasted strikingly with those of the latter, which previously has been inferred to have experienced a reduction in population size.

Primers based on GenBank sequences within the 5' untranslated region (UTR) of the human and horse tumour necrosis factor alpha (TNF-alpha) genes were designed and used to amplify a 522-bp product. Sequencing of five clones derived from five independent PCRs obtained from three different animals of three different breeds (Old Kladruber, Akhal-Teke and Shetland Pony) revealed a high level of sequence identity to the TNF-alpha promoter regions of other species. The existing GenBank horse sequences were confirmed and extended upstream by 230 nucleotides. Based on the sequence obtained, a new horse-specific forward primer was designed to amplify a 213-bp PCR product, which was screened for polymorphism using single-strand conformation polymorphism (SSCP). Three allelic variants of the horse TNF-alpha gene were identified and sequenced (GenBank accession numbers ADF 349558-60). Two single nucleotidepolymorphisms explained the existence of the three SSCP alleles detected: C/T and T/C single base pair substitutions at positions 137 and 147, respectively. Differences in allelic frequencies between Old Kladruber and Akhal-Teke breeds were observed. PMID:12121271

Background. The aim of the study was to investigate the association between single nucleotidepolymorphism (SNP) of vitamin D receptor (VDR) gene and clinical progress of benign prostatic hyperplasia (BPH) in Chinese men. Methods. The DNA was extracted from blood of 200 BPH patients with operation (progression group) and 200 patients without operation (control group), respectively. The genotypes of VDR gene FokI SNP represented by “F/f” were identified by PCR-restriction fragment length polymorphism. The odds ratio (OR) of having progression of BPH for having the genotype were calculated. Results. Our date indicated that the f alleles of the VDR gene FokI SNP associated with the progression of BPH (P = 0.009). Conclusion. For the first time, our study demonstrated that VDR gene FokI SNP may be associated with the risk of BPH progress. PMID:25685834

Dear Editor, The recent article by Mohammadzadeh et al.[1] on the latest issue of this Journal showed that the T allele +276G/T SNP of ADIPOQ gene is more associated with the increasing risk of coronary artery disease (CAD) in subjects with type 2 diabetes. Adipocytes were described in myocardial tissue of CAD patients and their role recently discussed[2,3]. Susceptibility to CAD by polymorphism in the Q gene of adiponectin has been reported for 3'-UTR, which harbours some genetic loci associated with metabolic risks and atherosclerosis[4]. Actually, previous studies have shown that the haplotype SNP +276G>T was associated with a decreased risk of CAD, after adjustment for potential confounding factors, therefore some controversial opinion still exists[5]. This evidence should be associated with the role exerted by adipocytes and adiponectin in heart physiology. In particular, in hypertensive disorder complicating pregnancy (HDCP), by investigating the population frequency of alleles, genotypes, and haplotypes of two single nucleotidepolymorphisms (SNPs), namely +45T>G (rs2241766) and +276G>T (rs1501299), some authors found that the SNP +276 TT genotype was significantly associated with protection against HDCP, when compared to the pooled G genotypes[6]. Moreover, the same +276G/T SNP haplotype was strongly associated with biliary atresia, an intractable neonatal inflammatory and obliterative cholangiopathy, leading to progressive fibrosis and cirrhosis[7]. CAD is closely related to adiponectin biology. The same isoforms of adiponectin seem to be not associated to CAD severity but to glucose metabolism and its impairment[8]. In the paper by Mohammadzadeh et al.[1], T allele in +276G/T SNP haplotype is highly associated with CAD in subjects with type 2 diabetes, but this linkage should be reappraised if related much more to diabetes rather than CAD. Association of T allele in the indicated SNP with CAD may be an indirect consequence of type 2 diabetes, as reported

Background The mapping of quantitative trait loci in rat and mouse has been extremely successful in identifying chromosomal regions associated with human disease-related phenotypes. However, identifying the specific phenotype-causing DNA sequence variations within a quantitative trait locus has been much more difficult. The recent availability of genomic sequence from several mouse inbred strains (including C57BL/6J, 129X1/SvJ, 129S1/SvImJ, A/J, and DBA/2J) has made it possible to catalog DNA sequence differences within a quantitative trait locus derived from crosses between these strains. However, even for well-defined quantitative trait loci (<10 Mb) the identification of candidate functional DNA sequence changes remains challenging due to the high density of sequence variation between strains. Description To help identify functional DNA sequence variations within quantitative trait loci we have used the Ensembl annotated genome sequence to compile a database of mouse single nucleotidepolymorphisms (SNPs) that are predicted to cause missense, nonsense, frameshift, or splice site mutations (available at ). For missense mutations we have used the PolyPhen and PANTHER algorithms to predict whether amino acid changes are likely to disrupt protein function. Conclusion We have developed a database of mouse SNPs predicted to cause missense, nonsense, frameshift, and splice-site mutations. Our analysis revealed that 20% and 14% of missense SNPs are likely to be deleterious according to PolyPhen and PANTHER, respectively, and 6% are considered deleterious by both algorithms. The database also provides gene expression and functional annotations from the Symatlas, Gene Ontology, and OMIM databases to further assess candidate phenotype-causing mutations. To demonstrate its utility, we show that Mouse SNP Miner successfully finds a previously identified candidate SNP in the taste receptor, Tas1r3, that underlies sucrose preference in the C57BL/6J strain. We also use Mouse

Background Although our microbial community and genomes (the human microbiome) outnumber our genome by several orders of magnitude, to what extent the human host genetic complement informs the microbiota composition is not clear. The Human Microbiome Project (HMP) Consortium established a unique population-scale framework with which to characterize the relationship of microbial community structure with their human hosts. A wide variety of taxa and metabolic pathways have been shown to be differentially distributed by virtue of race/ethnicity in the HMP. Given that mtDNA haplogroups are the maternally derived ancestral genomic markers and mitochondria’s role as the generator for cellular ATP, characterizing the relationship between human mtDNA genomic variants and microbiome profiles becomes of potential marked biologic and clinical interest. Results We leveraged sequencing data from the HMP to investigate the association between microbiome community structures with its own host mtDNA variants. 15 haplogroups and 631 mtDNA nucleotidepolymorphisms (mean sequencing depth of 280X on the mitochondria genome) from 89 individuals participating in the HMP were accurately identified. 16S rRNA (V3-V5 region) sequencing generated microbiome taxonomy profiles and whole genome shotgun sequencing generated metabolic profiles from various body sites were treated as traits to conduct association analysis between haplogroups and host clinical metadata through linear regression. The mtSNPs of individuals with European haplogroups were associated with microbiome profiles using PLINK quantitative trait associations with permutation and adjusted for multiple comparisons. We observe that among 139 stool and 59 vaginal posterior fornix samples, several haplogroups show significant association with specific microbiota (q-value

Purpose Tenomodulin (TNMD) is located in the X-chromosome encoding a putative angiogenesis inhibitor which is expressed in retina. Associations of single nucleotidepolymorphisms of TNMD with the prevalence of age-related macular degeneration (AMD) were examined. Methods Six markers covering 75% of the common sequence variation in the coding region of TNMD and 10 kb up- and downstream were genotyped in a sample consisting of 89 men and 175 women with exudative AMD, 18 men and 25 women with atrophic AMD, and 55 men and 113 women without AMD. All participants were over 65 years old and did not have diabetes mellitus. Due to the chromosomal locus, the association of genotypes with AMD was assessed genderwise. Results Three markers, rs1155974, rs2073163, and rs7890586, were associated with a risk of AMD in women. In comparison to women with other genotypes, the women who were homozygous for the minor allele (genotypes rs1155974-TT or rs2073163-CC) had 2.6 fold (p=0.021) or 1.9 fold (p=0.067) risk for having AMD, respectively. These differences were due to the unequal prevalence of exudative AMD. In comparison to women who were homozygous for the major alleles, the women with rs1155974-TT genotype had a 2.8 fold risk (p=0.021 in additive model; p=0.022 in recessive model) for exudative AMD, and the women with rs2073163-CC genotype had a 1.8 fold risk (p=0.09 in additive model; p=0.038 in recessive model). Furthermore, women carrying the rare rs7890586-AA genotype had a significantly smaller risk for having AMD than women with the other genotypes (odds ratio 0.083; p=0.001 in recessive model), but due to the low frequency of this genotype, this finding must be interpreted cautiously. The false discovery rate was <10% for all of the aforementioned results. Conclusions On the basis of the putative antiangiogenic role of TNMD and the present genetic associations of TNMD with AMD in women, we suggest that TNMD could be a novel candidate gene for AMD. These results should be

Dairy cows with increased rectal temperature experience lower milk yield and fertility. Rectal temperature during heat stress is heritable, so genetic selection for body temperature regulation could reduce effects of heat stress on production. One aim of the study was to validate the relationship between genotype and heat tolerance for single nucleotidepolymorphisms (SNPs) previously associated with resistance to heat stress. A second aim was to identify new SNPs associated with heat stress resistance. Thermotolerance was assessed in lactating Holsteins during the summer by measuring rectal temperature (a direct measurement of body temperature regulation; n = 435), respiration rate (an indirect measurement of body temperature regulation, n = 450) and sweating rate (the major evaporative cooling mechanism in cattle, n = 455). The association between genotype and thermotolerance was evaluated for 19 SNPs previously associated with rectal temperature from a genomewide analysis study (GWAS), four SNPs previously associated with change in milk yield during heat stress from GWAS, 2 candidate gene SNPs previously associated with rectal temperature and respiration rate during heat stress (ATPA1A and HSP70A) and 66 SNPs in genes previously shown to be associated with reproduction, production or health traits in Holsteins. For SNPs previously associated with heat tolerance, regions of BTA4, BTA6 and BTA24 were associated with rectal temperature; regions of BTA6 and BTA24 were associated with respiration rate; and regions of BTA5, BTA26 and BTA29 were associated with sweating rate. New SNPs were identified for rectal temperature (n = 12), respiration rate (n = 8) and sweating rate (n = 3) from among those previously associated with production, reproduction or health traits. The SNP that explained the most variation were PGR and ASL for rectal temperature, ACAT2 and HSD17B7 for respiration rate, and ARL6IP1 and SERPINE2 for sweating rate. ARL6IP1 was associated with all three

The STING (stimulator of interferon genes) protein can bind cyclic dinucleotides to activate the production of type I interferons and inflammatory cytokines. The cyclic dinucleotides can be bacterial second messengers c-di-GMP and c-di-AMP, 3’5’-3’5’ cyclic GMP-AMP (3’3’ cGAMP) produced by Vibrio cholerae and metazoan second messenger 2’5’-3’5’ Cyclic GMP-AMP (2’3’ cGAMP). Analysis of single nucleotidepolymorphism (SNP) data from the 1000 Genome Project revealed that R71H-G230A-R293Q (HAQ) occurs in 20.4%, R232H in 13.7%, G230A-R293Q (AQ) in 5.2%, and R293Q in 1.5% of human population. In the absence of exogenous ligands, the R232H, R293Q and AQ SNPs had only modest effect on the stimulation of IFN-β and NF-κB promoter activities in HEK293T cells, while HAQ had significantly lower intrinsic activity. The decrease was primarily due to the R71H substitution. The SNPs also affected the response to the cyclic dinucleotides. In the presence of c-di-GMP, the R232H variant partially decreased the ability to activate IFN-βsignaling, while it was defective for the response to c-di-AMP and 3’3’ cGAMP. The R293Q dramatically decreased the stimulatory response to all bacterial ligands. Surprisingly, the AQ and HAQ variants maintained partial abilities to activate the IFN-β signaling in the presence of ligands due primarily to the G230A substitution. Biochemical analysis revealed that the recombinant G230A protein could affect the conformation of the C-terminal domain of STING and the binding to c-di-GMP. Comparison of G230A structure with that of WT revealed that the conformation of the lid region that clamps onto the c-di-GMP was significantly altered. These results suggest that hSTING variation can affect innate immune signaling and that the common HAQ haplotype expresses a STING protein with reduced intrinsic signaling activity but retained the ability to response to bacterial cyclic dinucleotides. PMID:24204993

Availability of high-density single nucleotidepolymorphism (SNP) genotyping platforms provided unprecedented opportunities to enhance breeding programmes in livestock, poultry and plant species, and to better understand the genetic basis of complex traits. Using this genomic information, genomic breeding values (GEBVs), which are more accurate than conventional breeding values. The superiority of genomic selection is possible only when high-density SNP panels are used to track genes and QTLs affecting the trait. Unfortunately, even with the continuous decrease in genotyping costs, only a small fraction of the population has been genotyped with these high-density panels. It is often the case that a larger portion of the population is genotyped with low-density and low-cost SNP panels and then imputed to a higher density. Accuracy of SNP genotype imputation tends to be high when minimum requirements are met. Nevertheless, a certain rate of genotype imputation errors is unavoidable. Thus, it is reasonable to assume that the accuracy of GEBVs will be affected by imputation errors; especially, their cumulative effects over time. To evaluate the impact of multi-generational selection on the accuracy of SNP genotypes imputation and the reliability of resulting GEBVs, a simulation was carried out under varying updating of the reference population, distance between the reference and testing sets, and the approach used for the estimation of GEBVs. Using fixed reference populations, imputation accuracy decayed by about 0.5% per generation. In fact, after 25 generations, the accuracy was only 7% lower than the first generation. When the reference population was updated by either 1% or 5% of the top animals in the previous generations, decay of imputation accuracy was substantially reduced. These results indicate that low-density panels are useful, especially when the generational interval between reference and testing population is small. As the generational interval

GeneSeek (Neogen Corp., Lexington, KY) designed a new version of the GeneSeek Genomic Profiler HD BeadChip for Dairy Cattle, which originally had >77,000 single nucleotidepolymorphisms (SNP). A set of >140,000 SNP was selected that included all SNP on the existing GeneSeek chip, all SNP used in US national genomic evaluations, SNP that were possible functional mutations, and other informative SNP. Because SNP with a lower minor allele frequency might track causative variants better, 30,000 more SNP were selected from the Illumina BovineHD Genotyping BeadChip (Illumina Inc., San Diego, CA) by choosing SNP to maximize differences in minor allele frequency between a SNP being considered for the new chip and the 2 SNP that flanked it. Single-gene tests were included if their location was known and bioinformatics indicated relevance for dairy cattle. To determine which SNP from the new chip should be included in genomic evaluations, genotypes available from chips already in use were used to impute and evaluate the SNP set. Effects for 134,511 usable SNP were estimated for all breed-trait combinations; SNP with the largest absolute values for effects were selected (5,000 for Holsteins, 1,000 for Jerseys, and 500 each for Brown Swiss and Ayrshires for each trait). To increase overlap with the 60,671 SNP currently used for genomic evaluation, 12,094 more SNP with the largest effects were added. After removing SNP with many parent-progeny conflicts, 84,937 SNP remained. Three cutoff studies were conducted with 3 SNP sets to determine reliability gain over that for parent average when evaluations based on August 2011 data were used to predict December 2014 performance. Across all traits, mean Holstein reliability gains were 32.5, 33.4, and 32.0 percentage points for 60,671, 84,937, and 134,511 SNP, respectively. After genotypes from the new chip became available, the proposed set was reduced from 84,937 to 77,321 SNP to remove SNP that were not included during manufacture

The aim of the present study was to investigate the effect of single nucleotidepolymorphisms in the major histocompatibility complex (MHC) class II gene on resistance to Newcastle disease virus and body weight of the Thai indigenous chicken, Leung Hang Khao (Gallus gallus domesticus). Blood samples were collected for single nucleotidepolymorphism analysis from 485 chickens. Polymerase chain reaction sequencing was used to classify single nucleotidepolymorphisms of class II MHC. Body weights were measured at the ages of 3, 4, 5, and 7 months. Titres of Newcastle disease virus at 2 weeks to 7 months were determined and the correlation between body weight and titre was analysed. The association between single nucleotidepolymorphisms and body weight and titre were analysed by a generalized linear model. Seven single nucleotidepolymorphisms were identified: C125T, A126T, C209G, C242T, A243T, C244T, and A254T. Significant correlations between log titre and body weight were found at 2 and 4 weeks. Associations between single nucleotidepolymorphisms and titre were found for C209G and A254T, and between all single nucleotidepolymorphisms (except A243T) and body weight. The results showed that class II MHC is associated with both titre of Newcastle disease virus and body weight in Leung Hang Khao chickens. This is of concern because improved growth traits are the main goal of breeding selection. Moreover, the results suggested that MHC has a pleiotropic effect on the titre and growth performance. This mechanism should be investigated in a future study. PMID:26732325

Background The incidence of Alzheimer’s disease, particularly in developing countries, is expected to increase exponentially as the population ages. Continuing research in this area is essential in order to better understand this disease and develop strategies for treatment and prevention. Genome-wide association studies have identified several loci as genetic risk factors of AD aside from apolipoprotein E such as bridging integrator (BIN1), clusterin (CLU), ATP-binding cassette sub-family A member 7 (ABCA7), complement receptor 1 (CR1) and phosphatidylinositol binding clathrin assembly protein (PICALM). However genetic research in developing countries is often limited by lack of funding and expertise. This study therefore developed and validated a simple, cost effective polymerase chain reaction based technique to determine these single nucleotidepolymorphisms. Methods An allele-specific PCR method was developed to detect single nucleotidepolymorphisms of BIN1 rs744373, CLU rs11136000, ABCA7 rs3764650, CR1 rs3818361 and PICALM rs3851179 in human DNA samples. Allele-specific primers were designed by using appropriate software to permit the PCR amplification only if the nucleotide at the 3’-end of the primer complemented the base at the wild-type or variant-type DNA sample. The primers were then searched for uniqueness using the Basic Local Alignment Search Tool search engine. Results The assay was tested on a hundred samples and accurately detected the homozygous wild-type, homozygous variant-type and heterozygous of each SNP. Validation was by direct DNA sequencing. Conclusion This method will enable researchers to carry out genetic polymorphism studies for genetic risk factors associated with late-onset Alzheimer’s disease (BIN1, CLU, ABCA7, CR1 and PICALM) without the use of expensive instrumentation and reagents. PMID:23419238

Single nucleotidepolymorphism (SNP) detection has been used extensively for genetic association studies of diseases including cancer. For mass, yet accurate and more economic SNP detection we have optimized tetra primer amplification refractory mutation system polymerase chain reaction (ARMS PCR) to detect three SNPs in the cytochrome P450 2E1 (CYP2E1) gene locus; i.e. rs3813865, rs2070672 and rs3813867. The optimization system strategies used were (1) designing inner and outer primers; (2) determining of their optimum primer concentration ratios; and (3) determining of the optimum PCR annealing temperature. The tetra primer ARMS PCR result could be directly observed using agarose gel electrophoresis. The method succesfully determined three SNPs in CYP2E1 locus, the results being consistent with validation using DNA sequencing and restriction fragment length polymorphisms (RFLP). PMID:27509930

The incidence of malignant melanoma in the developed world is continuously increasing. We conducted a case–control study in order to evaluate the association between each of the four estrogen receptor alpha polymorphisms (ESR1 single-nucleotidepolymorphisms [SNPs] +2464C/T, −4576A/C, +1619A/G, and +6362C/T) and malignant melanoma susceptibility and disease course. The study population consisted of 205 Caucasian patients who were diagnosed as having malignant melanoma and 208 healthy Caucasian controls. Through DNA genotyping, we identified a SNP-dependent malignant melanoma susceptibility as well as a SNP-dependent effect on the course of disease and response to therapy. PMID:26949342

This study describes (1) the application of new methods to the discovery of informative single nucleotidepolymorphism (SNP) markers in chum salmon Oncorhynchus keta, (2) a method to resolve the linkage phase of closely linked SNPs and (3) a method to inexpensively genotype them. Finally, it demonstrates that these SNPs provide information that discriminates among O. keta populations from different geographical regions of the northern Pacific Ocean. These informative markers can be used in conjunction with mixed-stock analysis to learn about the spatial and temporal marine distributions of O. keta and the factors that influence the distributions. PMID:21133920

Trauma is a major public health problem worldwide. Infectious complications, sepsis, and multiple organ dysfunction syndrome (MODS) remain important causes for morbidity and mortality in patients who survive the initial trauma. There is increasing evidence for the role of genetic variation in the innate immune system on infectious complications in severe trauma patients. We describe a trauma patient with multiple infectious complications caused by multiple micro-organisms leading to prolonged hospital stay with numerous treatments. This patient had multiple single nucleotidepolymorphisms (SNPs) in the MBL2, MASP2, FCN2 and TLR2 genes, most likely contributing to increased susceptibility and severity of infectious disease. PMID:26312121

Here, we report the synthesis of a fluorescence resonance energy transfer (FRET)-based probe for single nucleotidepolymorphism (SNP) typing. The probe contains a fluorescent tricyclic base, 8-amino-3-(2,3-dihydroxypropyl)imidazo[4',5':5,6]pyrido[2,3-d]pyrimidine, as a donor molecule and 7-diethylaminocoumarin-3-carboxylic acid as an acceptor molecule. FRET was observed between the donor and acceptor molecules on the probe. The identity of the target bases on DNA and RNA strands could be determined using the probe. PMID:27329795

Premature ovarian failure (POF) is an ovarian defect characterized by the premature depletion of ovarian follicles in individuals <40 years old, and is a major cause of infertility in females. Genetic factors are considered to be responsible for the development of POF, however, the exact pathogenesis remains to be elucidated in the majority of cases. In the present study, the single nucleotidepolymorphisms (SNPs) of growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), inhibin βB (INHBB) and follicle stimulating hormone receptor (FSHR) genes were investigated, and their association with POF in a Chinese Hui population of the Ningxia Hui Autonomous Region in western China was evaluated. Peripheral blood samples were collected from 63 patients diagnosed with POF (POF group) and 58 normal control individuals (control group), from which the genomic DNA was isolated. The GDF9, BMP15, INHBB and FSHR genes were amplified using polymerase chain reaction assays, and their SNPs were determined by sequencing. In the four SNPs identified across the GDF9 loci, D57Y (169G>T), rs1049127 (546G>A), rs254286 (447C>T) and rs254285 (969C>G), the frequencies of the 546G>A genotype and allele A were significantly higher in the POF group, compared with the normal control group (34.92, vs. 6.90%; P<0.05 and 19.05, vs. 3.23%; P<0.05, repsectively), while no significant differences were observed in the occur rence of the c.447C>T and c.969C>G mutations between the two groups (60.32, vs. 50% and 50.79, vs. 55.17%, repsectively). The c.169G>T mutation within the GDF9 gene was only detected in two patients with POF, and the mutation did not occur in the normal control group. A total of three SNPs were detected within the BMP15 gene, including rs3810682 (−9C>G), rs79377927 (788_789insTCT) and rs17003221 (852C>T), and no significant differences were observed in the frequencies of the 9C>G and 852C>T genotypes between the POF and control groups (7.94, vs. 6.90% and 4

Examination of bovine pituitary gland transcriptome by strand-specific RNA-seq allows detection of putative single nucleotidepolymorphisms (SNPs) within potential candidate genes (CGs) or QTLs regions as well as to understand the genomics variations that contribute to economic trait. Here we report a breed-specific model to successfully perform the detection of SNPs in the pituitary gland of young growing bulls representing Polish Holstein-Friesian (HF), Polish Red, and Hereford breeds at three developmental ages viz., six months, nine months, and twelve months. A total of 18 bovine pituitary gland polyA transcriptome libraries were prepared and sequenced using the Illumina NextSeq 500 platform. Sequenced FastQ databases of all 18 young bulls were submitted to NCBI-SRA database with NCBI-SRA accession numbers SRS1296732. For the investigated young bulls, a total of 113,882,3098 raw paired-end reads with a length of 156 bases were obtained, resulting in an approximately 63 million paired-end reads per library. Breed-wise, a total of 515.38, 215.39, and 408.04 million paired-end reads were obtained for Polish HF, Polish Red, and Hereford breeds, respectively. Burrows-Wheeler Aligner (BWA) read alignments showed 93.04%, 94.39%, and 83.46% of the mapped sequencing reads were properly paired to the Polish HF, Polish Red, and Hereford breeds, respectively. Constructed breed-specific SNP-db of three cattle breeds yielded at 13,775,885 SNPs. On an average 765,326 breed-specific SNPs per young bull were identified. Using two stringent filtering parameters, i.e., a minimum 10 SNP reads per base with an accuracy ≥ 90% and a minimum 10 SNP reads per base with an accuracy = 100%, SNP-db records were trimmed to construct a highly reliable SNP-db. This resulted in a reduction of 95,7% and 96,4% cut-off mark of constructed raw SNP-db. Finally, SNP discoveries using RNA-Seq data were validated by KASP™ SNP genotyping assay. The comprehensive QTLs/CGs analysis of 76 QTLs

Inflammation plays a significant role in the etiology of type 2 diabetes mellitus (T2DM). The rise in the pro-inflammatory cytokines is the essential step in glucotoxicity and lipotoxicity induced mitochondrial injury, oxidative stress and beta cell apoptosis in T2DM. Among the recognized markers are interleukin (IL)-6, IL-1, IL-10, IL-18, tissue necrosis factor-alpha (TNF-α), C-reactive protein, resistin, adiponectin, tissue plasminogen activator, fibrinogen and heptoglobins. Diabetes mellitus has firm genetic and very strong environmental influence; exhibiting a polygenic mode of inheritance. Many single nucleotidepolymorphisms (SNPs) in various genes including those of pro and anti-inflammatory cytokines have been reported as a risk for T2DM. Not all the SNPs have been confirmed by unifying results in different studies and wide variations have been reported in various ethnic groups. The inter-ethnic variations can be explained by the fact that gene expression may be regulated by gene-gene, gene-environment and gene-nutrient interactions. This review highlights the impact of these interactions on determining the role of single nucleotidepolymorphism of IL-6, TNF-α, resistin and adiponectin in pathogenesis of T2DM. PMID:25987962

In tomato (Solanum lycopersicum) fruit, the number of locules (cavities containing seeds that are derived from carpels) varies from two to up to 10 or more. Locule number affects fruit shape and size and is controlled by several quantitative trait loci (QTLs). The large majority of the phenotypic variation is explained by two of these QTLs, fasciated (fas) and locule number (lc), that interact epistatically with one another. FAS has been cloned, and mutations in the gene are described as key factors leading to the increase in fruit size in modern varieties. Here, we report the map-based cloning of lc. The lc QTL includes a 1,600-bp region that is located 1,080 bp from the 3′ end of WUSCHEL, which encodes a homeodomain protein that regulates stem cell fate in plants. The molecular evolution of lc showed a reduction of diversity in cultivated accessions with the exception of two single-nucleotidepolymorphisms. These two single-nucleotidepolymorphisms were shown to be responsible for the increase in locule number. An evolutionary model of locule number is proposed herein, suggesting that the fas mutation appeared after the mutation in the lc locus to confer the extreme high-locule-number phenotype. PMID:21673133

Single nucleotidepolymorphisms (SNPs) are accumulated frequently in the mitochondrial displacement loop (D-loop) in various types of cancer, and their association with cancer risk and disease outcome has been extensively identified. We have identified specific risk-associated SNP for familial breast cancer patients previously. In this study, we investigated the association between age-at-onset and the SNPs in familial breast cancer patients. The SNP sites of nucleotides 16 311 T/C were identified for their association with age-at-onset using the log-rank test. The age-at-onset of the patients with the minor allele C genotype was significantly earlier than that of patients carrying the T genotype at the site 16 311 (p = 0.032). Accordingly, the genetic polymorphisms in the mitochondrial D-loop are predictive markers for age-at-onset in familial breast cancer patients, which may help to identify familial breast cancer patient subgroups at high risk of early onset. PMID:27158866

Inflammation plays a significant role in the etiology of type 2 diabetes mellitus (T2DM). The rise in the pro-inflammatory cytokines is the essential step in glucotoxicity and lipotoxicity induced mitochondrial injury, oxidative stress and beta cell apoptosis in T2DM. Among the recognized markers are interleukin (IL)-6, IL-1, IL-10, IL-18, tissue necrosis factor-alpha (TNF-α), C-reactive protein, resistin, adiponectin, tissue plasminogen activator, fibrinogen and heptoglobins. Diabetes mellitus has firm genetic and very strong environmental influence; exhibiting a polygenic mode of inheritance. Many single nucleotidepolymorphisms (SNPs) in various genes including those of pro and anti-inflammatory cytokines have been reported as a risk for T2DM. Not all the SNPs have been confirmed by unifying results in different studies and wide variations have been reported in various ethnic groups. The inter-ethnic variations can be explained by the fact that gene expression may be regulated by gene-gene, gene-environment and gene-nutrient interactions. This review highlights the impact of these interactions on determining the role of single nucleotidepolymorphism of IL-6, TNF-α, resistin and adiponectin in pathogenesis of T2DM. PMID:25987962

A central aim of evolutionary genomics is to identify the relative roles that various evolutionary forces have played in generating and shaping genetic variation within and among species. Here we use whole-genome resequencing data to characterize and compare genome-wide patterns of nucleotidepolymorphism, site frequency spectrum, and population-scaled recombination rates in three species of Populus: Populus tremula, P. tremuloides, and P. trichocarpa. We find that P. tremuloides has the highest level of genome-wide variation, skewed allele frequencies, and population-scaled recombination rates, whereas P. trichocarpa harbors the lowest. Our findings highlight multiple lines of evidence suggesting that natural selection, due to both purifying and positive selection, has widely shaped patterns of nucleotidepolymorphism at linked neutral sites in all three species. Differences in effective population sizes and rates of recombination largely explain the disparate magnitudes and signatures of linked selection that we observe among species. The present work provides the first phylogenetic comparative study on a genome-wide scale in forest trees. This information will also improve our ability to understand how various evolutionary forces have interacted to influence genome evolution among related species. PMID:26721855

Non-melanoma skin cancers (NMSC) are the most common form of human skin cancer. The majority of NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) with a BCC:SCC incidence ratio of 4:1 in immunocompetent patients. Toll-like receptors (TLRs) are transmembrane glycoproteins that recognize pathogen-associated molecular patterns and damage-associated molecular patterns, against which they activate the innate immune response and initiate the adaptive immune response. Genetic variations of these receptors can alter the immune system and are involved in evolution and susceptibility of various diseases, including cancer. Imiquimod, an agonist of TLR7, is applied topically in the treatment of premalignant and malignant skin disorders, in particular BCC. The high efficacy of this TLR7 agonist toward BCC supports a possible role of this receptor in the induction of BCC and, consequently, polymorphisms of this receptor could be responsible for a greater or lesser susceptibility to BCC. The aim of the present study was to evaluate whether the presence of the functional TLR7 rs179008/Gln11Leu promoter polymorphism conferred an increased susceptibility to BCC. A case-control study with 177 BCC cases and 158 controls was performed to highlight the possible association between this polymorphism and the susceptibility to BCC. As the TLR7 gene is localized on chromosome X, the allelic frequency of this polymorphism was analyzed separately in males and females. The analysis of the distribution of frequencies of wild-type TLR7 and variant TLR7 carrying the single-nucleotidepolymorphism (SNP) rs179008 in patients with BCC and healthy subjects did not reveal any statistically significant difference between cases and controls. This study does not suggest the involvement of the SNP rs179008 of TLR7 in the susceptibility to BCC, but cannot exclude a role for TLR7 in BCC carcinogenesis considering the high efficacy of the TLR7 agonist, imiquimod, in the treatment of this

Completed genome sequences provide templates for the design of genome analysis tools in orphan species lacking sequence information. To demonstrate this principle, we designed 384 PCR primer pairs to conserved exonic regions flanking introns, using Sorghum/Pennisetum expressed sequence tag alignments to the Oryza genome. Conserved-intron scanning primers (CISPs) amplified single-copy loci at 37% to 80% success rates in taxa that sample much of the approximately 50-million years of Poaceae divergence. While the conserved nature of exons fostered cross-taxon amplification, the lesser evolutionary constraints on introns enhanced single-nucleotidepolymorphism detection. For example, in eight rice (Oryza sativa) genotypes, polymorphism averaged 12.1 per kb in introns but only 3.6 per kb in exons. Curiously, among 124 CISPs evaluated across Oryza, Sorghum, Pennisetum, Cynodon, Eragrostis, Zea, Triticum, and Hordeum, 23 (18.5%) seemed to be subject to rigid intron size constraints that were independent of per-nucleotide DNA sequence variation. Furthermore, we identified 487 conserved-noncoding sequence motifs in 129 CISP loci. A large CISP set (6,062 primer pairs, amplifying introns from 1,676 genes) designed using an automated pipeline showed generally higher abundance in recombinogenic than in nonrecombinogenic regions of the rice genome, thus providing relatively even distribution along genetic maps. CISPs are an effective means to explore poorly characterized genomes for both DNA polymorphism and noncoding sequence conservation on a genome-wide or candidate gene basis, and also provide anchor points for comparative genomics across a diverse range of species. PMID:16607031

Single nucleotidepolymorphisms (SNPs) are widely employed in the studies of population genetics, molecular breeding and conservation genetics. In this study, we explored a simple route to develop SNPs from non-model species based on screening the library of single copy nuclear genes (SCNGs). Through application of this strategy in Panax, we identified 160 and 171 SNPs from P. quinquefolium and P. ginseng, respectively. Our results demonstrated that both P. ginseng and P. quinquefolium possessed a high level of nucleotide diversity. The number of haplotype per locus ranged from 1 to 12 for P. ginseng and from 1 to 9 for P. quinquefolium, respectively. The nucleotide diversity of total sites (πT) varied between 0.000 and 0.023 for P. ginseng and 0.000 and 0.035 for P. quinquefolium, respectively. These findings suggested that this approach is well suited for SNP discovery in non-model organisms and is easily employed in standard genetics laboratory studies. PMID:24351835

Current evidence suggests that the acquisition of female reproductive capacity and the maintenance of mature reproductive function are related processes transcriptionally regulated by gene networks operating within the neuroendocrine brain. One of these genes, termed enhanced at puberty 1 (EAP1), encodes an upstream regulator of these processes. Selective inhibition of EAP1 expression in discrete regions of the rat and nonhuman primate (NHP) hypothalamus, via targeted delivery of RNA interference, either disrupts (rats) or abolishes (monkeys) reproductive cycles. The striking loss of menstrual cyclicity resulting from knocking down hypothalamic EAP1 expression suggests that diminished EAP1 function may contribute to disorders of the menstrual cycle of neuroendocrine origin. Here we show that a single-nucleotidepolymorphism in the 5'-flanking region of EAP1 gene is associated with increased incidence of amenorrhea/oligomenorrhea in NHP. In the presence of the risk allele, binding of the transcription factor mothers against decapentaplegic homolog 3 (SMAD3) to its recognition site contained within the polymorphic sequence in the monkey EAP1 promoter is reduced. The risk allele also diminishes the increase in EAP1 promoter activity elicited by TGFβ1, a peptide that activates a SMAD3/4-mediated signaling pathway to regulate gene transcription. These findings indicate that common genetic variation in the EAP1 locus increases the susceptibility of NHP to loss/disruption of menstrual cyclicity. They also raise the possibility that polymorphisms in EAP1 may increase the risk of functional hypothalamic amenorrhea in humans. PMID:22128021

The Fas (APO-1, TNFRSF6) gene known as a member of the tumor necrosis factor receptor superfamily was selected for DNA marker development in Korean cattle. It is a cell membrane protein and mediates programmed cell death (apoptosis). We discovered single nucleotidepolymorphisms (SNPs) within Fas gene in order to develop novel DNA markers related to economical traits at the genomic level. The sequences of whole exon and 1 kb range of both front and back of the gene were determined by direct-sequencing methods using 24 cattle. A total of 55 SNPs were discovered and we selected 31 common polymorphic sites considering their allele frequencies, haplotype-tagging status and linkage disequilibrium (LD) for genotyping in larger-scale subjects. The SNPs were confirmed genotype through the SNaPshot method (n = 274) and were examined for a possible genetic association between Fas polymorphisms and marbling score. So, the SNPs that were identified significant are g.30256G>C, g.31474C>A, g.31940A>G, and g.32982G>A. These results suggest that SNPs of Fas gene were associated with intramuscular fat content of meat quality traits in Korean cattle. PMID:26732324

An atovaquone (ATV)-resistant Babesia gibsoni was developed by in vitro exposure of uncloned wild type (WT) B. gibsoni to 800 nM ATV for 6 days. Sequence analysis of mitochondrial genes showed a single-nucleotidepolymorphism (SNP) at cytb nt363 (G to T) that resulted in the substitution of methionine with isoleucine (M121I), which is one of the SNPs reported in a previous in vivo study. 363T or 363G allele-specific real-time polymerase chain reaction (PCR) revealed that an M121I variant was present in over 99% of the ATV-resistant population. As neither ATV resistance nor gene polymorphisms appeared in the B. gibsoni WT sibling clones, the expression of ATV resistance in this study was suspected to be because of selective multiplication of the B. gibsoni M121I variant. This ATV-resistant B. gibsoni displayed the same sensitivity as the WT B. gibsoni against 5 other drugs, including diminazene aceturate, azithromycin, doxycycline, clindamycin, and proguanil. This is the first report on the in vitro establishment of an ATV-resistant B. gibsoni with gene polymorphisms. PMID:21996003

The common carp (Cyprinus carpio) is an important aquaculture fish worldwide but only limited single nucleotidepolymorphism (SNP) markers are characterized from expressed sequence tags (ESTs) in this species. In this study, 1487 putative SNPs were bioinformatically mined from 14,066 online ESTs mainly from the European common carp, with the occurrence rate of about one SNP every 173 bp. One hundred and twenty-one of these SNPs were selected for validation using PCR fragment sequencing, and 48 out of 81 primers could amplify the expected fragments in the Chinese common carp genome. Only 26 (21.5%) putative SNPs were validated, however, 508 new SNPs and 68 indels were identified. The ratios of transitions to transversions were 1.77 for exon SNPs and 1.05 for intron SNPs. All the 23 SNPs selected for population tests were polymorphic, with the observed heterozygosity (Ho) ranging from 0.053 to 0.526 (mean 0.262), polymorphism information content (PIC) from 0.095 to 0.357 (mean 0.246), and 21 SNPs were in Hardy-Weinberg equilibrium. These results suggest that different common carp populations with geographic isolation have significant genetic variation at the SNP level, and these new EST-SNP markers are readily available for genetics and breeding studies in common carp. PMID:22837697

Reduced expression of human leukocyte antigen-G (HLA-G) has been linked to onset of preeclampsia. Associations have also been reported between preeclampsia and single nucleotidepolymorphisms (SNP) in the 3′-untranslated region (UTR) of the HLA-G gene. However, there are conflicting results between studies. This studied examined whether a SNP, by itself or in combination with other SNPs, in the 3′UTR of the HLA-G gene is associated with an increased risk of preeclampsia. Placenta samples were obtained from 47 preeclamptic and 68 control cases. DNA was extracted, and the 3′UTR was sequenced and analyzed for nine polymorphisms using different genetic models of inheritance. Four of these polymorphisms have never been analyzed for an association with preeclampsia. Disputing existing reports, preeclamptic cases were suggestively associated with a G/G-genotype at SNP +3187 (p < 0.05). Several SNP combinations were more prevalent in preeclampsia cases. Following corrections for multiple testing, one SNP combination (+3027C/C and +3187G/G) was significantly more prevalent in preeclampsia cases using co-dominant, additive, and dominant models (p < 0.001). Taken together with the current literature, the data suggests that HLA-G 3′UTR SNP-pair associations, and not individual SNPs, could be useful in a predictive test for the susceptibility to preeclampsia. PMID:25454622

Synaptosomal-associated protein of 25 kDa (SNAP-25) is an age-regulated vesicular SNARE protein involved in the exocytosis of neurotransmitters from synapses, a process that is altered in Alzheimer's disease (AD). Changes in SNAP-25 levels are suggested to contribute to age-related decline of cognitive function, and single nucleotidepolymorphisms (SNPs) in the SNAP-25 gene are present in neuropsychiatric conditions and play a role in determining IQ phenotypes. To verify a possible role of SNAP-25 in AD, we analyzed five gene polymorphisms in patients with AD (n = 607), replicating the study in subjects with amnestic mild cognitive impairment (aMCI) (n = 148) and in two groups of age-matched healthy controls (HC1: n = 615 and HC2: n = 310). Results showed that the intronic rs363050 (A) and rs363043 (T) alleles, as well as the rs363050/rs363043 A-T haplotype are significantly more frequent in AD and aMCI and are associated with pathological scores of categorical fluency in AD. Notably, functional MRI analyses indicated that SNAP-25 genotypes correlate with a significantly decreased brain activity in the cingulate cortex and in the frontal (middle and superior gyri) and the temporo-parietal (angular gyrus) area. SNAP-25 polymorphisms may be associated with AD and correlate with alterations in categorical fluency and a reduced localized brain activity. SNAP-25 polymorphisms could be used as surrogate markers for the diagnosis of AD and of cognitive deficit; these SNPs might also have a possible predictive role in the natural history of AD. PMID:25024311

Aim: Toll-like receptor 2 (TLR2) and TLR4 genes play critical roles in host recognition of Mycobacterium bovis infection and initiation of innate and adaptive immune response. The present study was aimed at exploring the association of seven single nucleotidepolymorphisms (SNPs) in TLR2 and TLR4 genes with susceptibility/resistance against bovine tuberculosis (bTB) infection in cattle. Materials and Methods: A case-control resource population of 35 positive and 45 negative animals was developed after screening with single intradermal tuberculin test for bTB. Resource population was screened for SNPs in TLR2 and TLR4 genes using polymerase chain reaction-restriction fragment length polymorphism. The PROC LOGISTIC procedure of SAS 9.3 was used to find an association of allelic and genotypic frequencies with bTB. Results: In TLR2 gene, two of SNPs under study (rs55617172 and rs68268253) revealed polymorphism while in the case of TLR4 gene all four SNPs under investigation (rs8193041, rs207836014, rs8193060, and rs8193069) were found to be polymorphic in case-control population. SNP locus rs55617172 in TLR2 gene was found significantly (p<0.01) associated with susceptibility/resistance to TB in cattle. Conclusion: These findings indicate the presence of SNPs in TLR2 and TLR4 genes in our resource population. Upon validation in independent, large resource population and following biological characterization, SNP rs55617172 can be incorporated in marker panel for selection of animals with greater resistance to bTB. PMID:27284220

The human major vault protein (MVP) has been linked to the development of multidrug resistance in cancer cells, and overexpression of MVP has been observed in ovarian cancer tissues. The aim of the present study was to investigate the association between single nucleotidepolymorphisms (SNPs) in the MVP gene and the tumor response to platinum-based chemotherapy and survival of patients affected by epithelial ovarian cancer (EOC), in addition to confirm whether tetra-primer amplification-refractory mutation system (ARMS)-polymerase chain reaction (PCR) is an accurate genotyping method. For this purpose, two polymorphisms in the MVP gene, namely reference SNP (rs)1057451 and rs4788186, were selected from the data obtained by the International haplotype map (HapMap) Project regarding Chinese Han population, and were evaluated by tetra-primer ARMS-PCR. Upon validation by DNA sequencing, the association of these polymorphisms with platinum resistance, progression-free survival (PFS) and overall survival (OS) in patients with EOC was assessed. The results of tetra-primer ARMS-PCR were in agreement with those derived from DNA sequencing. No significant differences were observed between platinum-sensitive and platinum-resistant cohorts in terms of allele and genotype distribution of these two polymorphisms in the MVP gene, which were not associated with PFS or OS. However, a trend toward prolonged PFS was observed in patients carrying the heterozygous AG allele at the rs4788186 locus. These results suggest that rs1057451 and rs4788186 variants in the MVP gene are not associated with favorable therapeutic response to platinum or longer survival in Chinese Han patients affected by EOC. In addition, the data of the present study confirm that tetra-primer ARMS-PCR is a trustworthy and economical genotyping method. PMID:27073578

The lung cancer mortality rate in Xuan Wei County, China is among the highest in the country and has been etiologically attributed to exposure to indoor smoky coal emissions that contain very high levels of polycyclic aromatic hydrocarbons (PAHs). Nucleotide excision repair (NE...

Leptin is a hormone that affects the regulation of body weight, energy expenditure, fat metabolism, food intake, and appetite. In this study, we cloned the jlLEP-A1 and jlLEP-A2 genes in Jian carp (Cyprinus carpio var. Jian) and performed an association analysis between identified polymorphisms and growth traits. Three polymorphisms in exons of jlLEP-A1 (A1-T113C) and jlLEP-A2 (A2-G415A and A2-G427A) were identified, and genotyped by the polymerase chain reaction - restriction fragment length polymorphism method in 263 female and 294 male Jian carp. All three SNPs were missense mutations. Association analysis revealed that the three SNPs were significantly associated with growth traits in male Jian carp. Only SNP A1-T113C was significantly associated with growth traits in female Jian carp. Analysis of diplotypes derived from jlLEP-A2 SNPs revealed an association with growth traits in male but not female Jian carp. These results demonstrate that polymorphisms in the leptin gene are associated with growth traits and may be used for marker-assisted selection programs in Jian carp breeding and production. PMID:27525905

Recent studies indicated that the aberrant gene expression of peroxiredoxin-6 (prdx6) was found in various kinds of cancers. Because of its biochemical function and gene expression pattern in cancer cells, the association between genetic polymorphism of Prdx6 and cancer onset is interesting. In this report, we have developed and implemented a…

Background In Taiwan, oral cancer has causally been associated with environmental carcinogens. Intercellular adhesion molecule (ICAM)-1, a cell adhesion molecule with a key role in inflammation and immunosurveillance, was implicated in carcinogenesis by facilitating instability in the tumor environment. The current study explored the combined effect of ICAM-1 gene polymorphisms and exposure to environmental carcinogens on the susceptibility of developing oral squamous cell carcinoma (OSCC) and the clinicopathological characteristics of the tumors. Methodology and Principal Findings Four single-nucleotidepolymorphisms (SNPs) of the ICAM-1 gene from 595 patients with oral cancer and 561 non-cancer controls were analyzed by a real-time PCR. We found that the ICAM-1 rs5498 polymorphism and the TAGG or TACG haplotype of 4 ICAM-1 SNPs (rs3093030, rs5491, rs281432, and rs5498) combined were associated with oral-cancer susceptibility. Among 727 smokers, ICAM-1 polymorphisms carriers with the betel-nut chewing habit had a 27.49–36.23-fold greater risk of having oral cancer compared to ICAM-1 wild-type (WT) carriers without the betel-nut chewing habit. Among 549 betel-nut chewers, ICAM-1 polymorphisms carriers who smoked had a 9.93–14.27-fold greater risk of having oral cancer compared to those who carried the WT but did not smoke. Finally, patients with oral cancer who had at least 1 T allele of ICAM-1 rs5491 or 1 G allele of rs281432 were at lower risk of developing an advanced clinical stage (III/IV) (p<0.05), compared to those patients with AA or CC homozygotes. Conclusions Our results suggest that the ICAM-1 rs5498 SNP and either of 2 haplotypes of 4 SNPs combined have potential predictive significance in oral carcinogenesis. Gene-environment interactions of ICAM-1 polymorphisms, smoking, and betel-nut chewing might alter oral-cancer susceptibility. ICAM-1 rs5491 and rs281432 may be applied as factors to predict the clinical stage in OSCC patients. PMID:24069166

Anti-inflammatory cytokines have an important role in disease, tumour and transplant processes. Alterations in the regulation of several cytokines have been implicated in a variety of inflammatory disorders, including IBD (inflammatory bowel disease) [Crohn's disease (CD) and ulcerative colitis (UC)]. Cytokine polymorphisms are also known to affect the level of gene expression. Thus, the aim of this study was to determine the relationship between cytokine polymorphisms and the IBD pathologies in a Spanish population. Polymorphisms analysis was performed using PCR-SSOP using a microbeads luminex assay. The following polymorphisms were determined: TNFα [-238G/A (rs361525) and -308G/A (rs1800629)], IFNγ [+874A/T (rs62559044)], TGFβ [+869C/T (rs1982073) and +915G/C (rs1800471)], IL10 [-1082A/A (rs1800896), -592A/C (rs1800872), -819C/T (rs1800871)], IL6 [-174C/G (rs1800795)], IL12p40 [3'UTR -1188A/C (rs3212227)], IL1α [-889C/T (rs1800587)], IL1β [-511C/T (rs1143634) and +3962C/T (rs1143633)], IL1R [Pst-1 1970C/T] and IL1RA [Mspa-1 11100C/T]. No statistical differences in TNFα, IFNγ, TGFβ, IL10, IL6, IL1α, IL1β, IL1R and IL1Ra genotypes and allele distributions between the IBD groups and healthy controls were found. However, we observed significant differences in the 3'UTR -1188A/C polymorphism of IL12p40. So -1188A allele was increased in patients with UC and the -1188C allele (high IL12p40 production) was increased in patients with CD with respect to controls. These data are in concordance with the fact that CD has been shown to be associated with a Th1 T-cell-mediated inflammation model and high IL12/IFNγ production at histological affected sites. These data suggest that cytokine polymorphisms in TNFα, IFNγ, TGFβ, IL10, IL6 and IL1α, IL1β, IL1R and IL1Ra cytokine gene do not seem to be relevant in IBD susceptibility and IL12p40 3'UTR -1188A/C polymorphism seems to be associated with a differential IBD development. PMID:25359546

Cutaneous melanoma is a life-threatening skin cancer. Its incidence is rapidly increasing, and early diagnosis is the main factor able to improve its poor prognosis. Toll-like receptors (TLRs) are transmembrane glycoproteins that recognize pathogen- and damage-associated molecular patterns, against which TLRs activate the innate immune response and initiate the adaptive immune response. Genetic variations of these receptors may alter the immune system, and are involved in evolution and susceptibility to various diseases, including cancer. The aim of the present study was to evaluate whether the presence of TLR7 glutamine (Gln) 11 leucine (Leu) polymorphism confers an increased susceptibility to cutaneous melanoma. For that purpose, a case-control study was performed with 182 melanoma cases and 89 controls. To highlight the possible association between the aforementioned polymorphism and the susceptibility to melanoma, 93 cases of single melanoma and 89 cases of multiple primary melanoma (MPM) were compared in the present study. Since the TLR7 gene is localized on the chromosome X, the allelic frequency of the Gln11Leu polymorphism was analyzed separately in males and females. The distribution of allele frequencies between melanoma cases and controls (P=0.245) and between single melanoma and MPM cases (P=0.482) was not significant. Therefore, the present results do not suggest an association between TLR7 Gln11Leu polymorphism and susceptibility to cutaneous melanoma. Further studies are required to analyze the influence of other TLR polymorphisms on the susceptibility to malignant melanoma and the involvement of innate immunity in this malignancy. PMID:27347137

SNUFER is a software for the automatic localization and generation of tables used for the presentation of single nucleotidepolymorphisms (SNPs). After input of a fasta file containing the sequences to be analyzed, a multiple sequence alignment is generated using ClustalW ran inside SNUFER. The ClustalW output file is then used to generate a table which displays the SNPs detected in the aligned sequences and their degree of similarity. This table can be exported to Microsoft Word, Microsoft Excel or as a single text file, permitting further editing for publication. The software was written using Delphi 7 for programming and FireBird 2.0 for sequence database management. It is freely available for noncommercial use and can be downloaded from http://www.heranza.com.br/bioinformatica2.htm. PMID:19238196

Single-nucleotidepolymorphisms (SNPs) are one of the main causes of evolution. The distribution of human SNPs, which were examined in detail genomewide, was analyzed. Three discrete databases of human SNPs were used for this analysis, and similar results were obtained from these databases. It was found that the distribution of the distance between SNPs was approximated by the power law, and the shape of the regions including SNPs had the so-called fractal structure. Although the reason why the distribution of SNPs obeys such a certain law of physics is unclear, a speculation was attempted in connection with the three-dimensional structure of human chromatin which has a fractal structure. PMID:27030000

Genetics of autoimmune diseases represent a growing domain with surpassing biomarker results with rapid progress. The exact cause of Rheumatoid Arthritis (RA) is unknown, but it is thought to have both a genetic and an environmental bases. Genetic biomarkers are capable of changing the supervision of RA by allowing not only the detection of susceptible individuals, but also early diagnosis, evaluation of disease severity, selection of therapy, and monitoring of response to therapy. This review is concerned with not only the genetic biomarkers of RA but also the methods of identifying them. Many of the identified genetic biomarkers of RA were identified in populations of European and Asian ancestries. The study of additional human populations may yield novel results. Most of the researchers in the field of identifying RA biomarkers use single nucleotidepolymorphism (SNP) approaches to express the significance of their results. Although, haplotype block methods are expected to play a complementary role in the future of that field. PMID:26843965

In this study, we developed the first genetic linkage map for the major rice insect pest, the brown planthopper (BPH, Nilaparvata lugens). The linkage map was constructed by integrating linkage data from two backcross populations derived from three inbred BPH strains. The consensus map consists of 474 simple sequence repeats, 43 single-nucleotidepolymorphisms, and 1 sequence-tagged site, for a total of 518 markers at 472 unique positions in 17 linkage groups. The linkage groups cover 1093.9 cM, with an average distance of 2.3 cM between loci. The average number of marker loci per linkage group was 27.8. The sex-linkage group was identified by exploiting X-linked and Y-specific markers. Our linkage map and the newly developed markers used to create it constitute an essential resource and a useful framework for future genetic analyses in BPH. PMID:23204257

We report a simple, rapid and low-cost test, based on gold nanoparticles, for the naked-eye colorimetric detection of a signature of single nucleotidepolymorphisms (SNPs) relevant for the personalized medicine of psoriasis patients. We validated the colorimetric assay on real-world DNA samples from a cohort of 30 psoriasis patients and we compared the results, in double-blind, with those obtained with two state-of-the-art instrumental techniques, namely reverse dot blotting and direct sequencing, finding 100% agreement. We demonstrated high accuracy, sensitivity and specificity of the colorimetric test that can be easily adapted for the genotypization of different SNPs, important for the pharmacogenomics of various diseases, and in other fields, such as food traceability and population structure analysis.

The completion of the human genome project and the construction of single nucleotidepolymorphism (SNP) maps have lead to significant efforts to find SNPs that can be linked to pathophysiology. In silico models of complete biochemical reaction networks relate a cell's individual reactions to the function of the entire network. Sequence variations can in turn be related to kinetic properties of individual enzymes, thus allowing an in silico model-driven assessment of the effects of defined SNPs on overall cellular functions. This process is applied to defined SNPs in two key enzymes of human red blood cell metabolism: glucose-6-phosphate dehydrogenase and pyruvate kinase. The results demonstrate the utility of in silico models in providing insight into differences between red cell function in patients with chronic and nonchronic anemia. In silico models of complex cellular processes are thus likely to aid in defining and understanding key SNPs in human pathophysiology. PMID:12421755

Background African American women more often present with more aggressive types of breast cancer than Caucasian women, but little is known whether genetic polymorphisms specific to or disproportionate in African Americans are associated with their risk of breast cancer. Methods A population-based case-control study was conducted including 194 cases identified through the Metropolitan Detroit Cancer Surveillance System and 189 controls recruited through random digit dialing to examine polymorphisms in genes involved in estrogen metabolism and action. Results The African American-specific CYP1A1 5639C allele was associated with an increased risk of breast cancer (odds ratio(OR)=2.34, 95%confidence interval (CI): 1.23–4.44) and this association with the CYP1A1 5639 locus was dependent on another polymorphism in the CYP3A4 gene (P=0.043 for the interaction). In addition, African American-predominant CYP1B1 432 Val allele was significantly more often found in the cases than in the controls overall and the HSD17B1 312 Gly allele was specifically associated with premenopausal breast cancer risk (OR=3.00, 95% CI: 1.29–6.99). Conclusion These observations need to be confirmed in larger studies due to the limited statistical power of the study based on a small number of cases. PMID:19679043

A single nucleotidepolymorphism (SNP) is a difference in the DNA sequence of one nucleotide only. We recently proposed a lab-on-a-chip (LoC) system which has the potentiality of fast, sensitive and highly specific SNP detection. Most of the chip components are silicon based and fabricated within a single process. In this paper, the newly developed fabrication method for the silicon chip is presented. The robust and reliable process allows etching structures on the same chip with very different aspect ratios. The characterization of a crucial component to the LoC SNP detector, the microreactor where DNA amplification is performed, is also detailed. Thanks to innovative design and fabrication methodologies, the microreactor has an excellent thermal isolation from the surrounding silicon substrate. This allows for highly localized temperature control. Furthermore, the microreactor is demonstrated to have rapid heating and cooling rates, allowing for rapid amplification of the target DNA fragments. Successful DNA amplification in the microreactor is demonstrated.

Salmonid genomes are considered to be in a pseudo-tetraploid state as a result of an evolutionarily recent genome duplication event. This situation complicates single nucleotidepolymorphism (SNP) discovery in rainbow trout as many putative SNPs are actually paralogous sequence variants (PSVs) and ...

Background Cattle are a reservoir of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157), and are known to harbor subtypes not typically found in clinically-ill humans. Consequently, nucleotidepolymorphisms previously discovered via isolates originating from human outbreaks may be restricte...

The objective was to determine if single nucleotidepolymorphisms (SNPs) in the ANKRA2 and CD180 genes were associated with incidence of bovine respiratory disease (BRD) and presence of Mycobacterium avium subsp. paratuberculosis (MAP) in cattle. Two independent populations were used. The first po...

Previous studies have established the presence of genetic variation on bovine chromosome 20 affecting a range of infectious disease-related phenotypes. The objective was to determine if single nucleotidepolymorphisms (SNP) in the ANKRA2 and RP105 genes were associated with incidence of bovine resp...

Background Cattle are a reservoir of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157), and are known to harbor subtypes not typically found in clinically-ill humans. Consequently, nucleotidepolymorphisms previously discovered via isolates originating from human outbreaks may be restricte...

Nearly 57,000 single nucleotidepolymorphisms (SNP) on the Illumina BovineSNP50™ chip were investigated to determine their usefulness for genomic prediction. Genotypes were obtained for 12,591 Holstein bulls and cows and SNP selection was done using 5,503 bulls that had genotypes on a larger set of ...

Previously, a candidate gene approach identified 51 single nucleotidepolymorphisms (SNP) associated with genetic merit for reproductive traits and 26 associated with genetic merit for production in dairy bulls. We evaluated association of the 77 SNPs with days open (DO) for first lactation in a pop...

The periodic need to restock reagent pools for genotyping chips provides an opportunity to increase the number of single-nucleotidepolymorphisms (SNP) on a chip at no increase in cost. A high-density chip with >140,000 SNP has been developed by GeneSeek Inc. (Lincoln, NE) to increase accuracy of ge...

Single nucleotidepolymorphisms (SNPs) are the fundamental unit of genetic variation and are applied as molecular tools for genetic mapping, breeding, germplasm characterization, taxonomy, and evaluation of distinctness, uniformity and stability (DUS). We report 29 novel SNPs in 10 EST and COSII ma...

Continued validation of genetic markers for economically important traits is crucial to establishing marker-assisted selection as a tool in the cattle industry. The objective of the present study was to evaluate the association of a single nucleotidepolymorphism (T9/T10) in the Osteopontin gene (S...

Large datasets containing single nucleotidepolymorphisms (SNPs) are used to analyze genome-wide diversity in a robust collection of cultivars from representative accessions, across the world. The extent of linkage disequilibrium (LD) within a population determines the number of markers required fo...

Single NucleotidePolymorphism (SNP) markers are increasingly being used in crop breeding programs, slowly replacing Simple Sequence Repeats (SSR) and other markers. SNPs provide many benefits over SSRs, including ease of analysis and unambiguous results across various platforms. We have identifie...

Single nucleotidepolymorphisms (SNPs), which are the most abundant form of genetic variations in numerous organisms, have emerged as important tools for the study of complex genetic traits and deciphering of genome evolution. High-throughput genome sequencing projects worldwide provide an unprecedented opportunity for whole-genome SNP analysis in a variety of species. To facilitate SNP discovery in vertebrates, we have developed a web-based, user-friendly, and fully automated application, DigiPINS, for genome-wide identification of exonic SNPs from EST data. Currently, the database can be used to the mining of exonic SNPs in six complete genomes (Homo sapiens, Mus musculus, Rattus norvegicus, Canis familiaris, Gallus gallus and Danio rerio). In addition to providing information on sequence conservation, DigiPINS allows compilation of comprehensive sets of polymorphisms within cancer candidate genes or identification of novel cancer markers, making it potentially useful for cancer association studies. The DigiPINS server is available via the internet at http://pbil.univ-lyon1.fr/gem/DigiPINS/query_DigiPINS.php. PMID:17988782

Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotidepolymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species. PMID:26901189

Cassava (Manihot esculenta) is an important staple crop, especially in the arid tropics. Because roots of commercial cassava cultivars contain a limited amount of provitamin A carotenoids, both conventional breeding and genetic modification are being applied to increase their production and accumulation to fight vitamin A deficiency disorders. We show here that an allelic polymorphism in one of the two expressed phytoene synthase (PSY) genes is capable of enhancing the flux of carbon through carotenogenesis, thus leading to the accumulation of colored provitamin A carotenoids in storage roots. A single nucleotidepolymorphism present only in yellow-rooted cultivars cosegregates with colored roots in a breeding pedigree. The resulting amino acid exchange in a highly conserved region of PSY provides increased catalytic activity in vitro and is able to increase carotenoid production in recombinant yeast and Escherichia coli cells. Consequently, cassava plants overexpressing a PSY transgene produce yellow-fleshed, high-carotenoid roots. This newly characterized PSY allele provides means to improve cassava provitamin A content in cassava roots through both breeding and genetic modification. PMID:20889914

Based on the concept of the individualized nature of sepsis, we investigated the significance of the -251 A/T (rs4073) single nucleotidepolymorphism (SNP) of interleukin (IL)-8 in relation to the underlying infection. Genotyping was performed in 479 patients with severe acute pyelonephritis (UTI, n = 146), community-acquired pneumonia (CAP, n = 109), intra-abdominal infections (IAI, n = 119), and primary bacteremia (BSI, n = 105) by restriction fragment length polymorphism of the polymerase chain reaction (PCR) product and compared with 104 healthy volunteers. Circulating IL-8 was measured within the first 24 h of diagnosis by an immunosorbent assay. Carriage of the AA genotype was protective from the development of UTI (odds ratio 0.38, p: 0.007) and CAP (odds ratio 0.30, p: 0.004), but not from IAI and BSI. Protection from the development of severe sepsis/septic shock was provided for carriers of the AA genotype among patients with UTI (odds ratio 0.15, p: 0.015). This was accompanied by greater concentrations of circulating IL-8 among patients with the AA genotype. It is concluded that carriage of rs4073 modifies susceptibility for severe infection in an individualized way. This is associated with a modulation of circulating IL-8. PMID:26768584

Single nucleotidepolymorphisms (SNPs) are the most abundant sequence variations found in plant genomes and are widely used as molecular genetic markers in genetic diversity studies and crossbreeding programs. In this study, we examined 113 DNA sequences of the endopolygalacturonase (endo-PG) gene from 67 peach accessions and found a total of 56 SNPs and 6 insertion/deletions (indels), with a frequency of 3, 1, and 3% for the transitions, transversions, and indels, respectively. Meanwhile, the majority of the observed SNPs were found in the intron regions, while only 2 variable sites and a single indel were detected in the exon regions. A dendrogram was obtained using neighbor-joining cluster analysis and divided into 2 main groups, providing evidence that most of the accessions of the clingstone nonmelting flesh phenotypes generally clustered together and were comparatively nonrelated to the "stony hard" peach cultivars, which were in a different branch altogether. Furthermore, 4 major haplotypes were formed and 3 cleaved amplified polymorphic sequence primer sets were mined according to fruit texture and stone adhesion, displaying their potential as candidate molecular markers for discriminating genotypes. This research will assist peach genetic enhancement by introducing a novel crossbreeding strategy. PMID:25966181

Dystrobrevin binding protein 1 (DTNBP1) gene is pivotal in regulating the glutamatergic system. Genetic variants of the DTNBP1 affect cognition and thus may be particularly relevant to schizophrenia. We therefore evaluated the association of six single nucleotidepolymorphisms (SNPs) with schizophrenia in a Malaysian population (171 cases; 171 controls). Associations between these six SNPs and schizophrenia were tested in two stages. Association signals with p < 0.05 and minor allele frequency > 0.05 in stage 1 were followed by genotyping the SNPs in a replication phase (stage 2). Genotyping was performed with sequenced specific primer (PCR-SSP) and restriction fragment length polymorphism (PCR-RFLP). In our sample, we found significant associations between rs2619522 (allele p = 0.002, OR = 1.902, 95%CI = 1.266 – 2.859; genotype p = 0.002) and rs2619528 (allele p = 0.008, OR = 1.606, 95%CI = 1.130 – 2.281; genotype p = 6.18 × 10−5) and schizophrenia. Given that these two SNPs may be associated with the pathophysiology of schizophrenia, further studies on the other DTNBP1 variants are warranted. PMID:26273215

This study was undertaken to determine the prevalence of dengue clinical symptom persistence during 60days of disease follow up, in patients of Espírito Santo state (ES)-Brazil and to evaluate the relation of single nucleotidepolymorphisms (SNPs) in FcγRIIa, CD209, VDR, TNF-α, IL-4, IL-6 and IFN-γ genes with symptom persistence. During 2012-2013, 96 blood samples from individuals diagnosed with symptomatic dengue were collected. Clinical symptom persistence in 60days of follow-up was assessed by a clinical and epidemiological questionnaire filled in 4 interviews. SNP genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In two months of monitoring the dengue infection, we observed that symptoms persisted in 38.5% (37/96) of dengue patients at the end of the first month (D30) and in 11.5% (11/96) of dengue patients at the end of the second month (D60). Our results show an association between FcγRIIa, TNF-α and IL-6 gene SNPs and symptom persistence and an association trend with CD209, IL-4 and IFN-γ gene SNPs. Our findings may increase the knowledge on the pathophysiological mechanisms of persistent symptoms of infection with the dengue virus (DENV) and thus help the clinical management of patients. PMID:26429310

The prevention and control of bovine mastitis by enhancing natural defenses in animals is important to improve the quality of dairy products. Mastitis resistance is a complex trait which depends on genetic components, as well as environmental and physiological factors. The limitations of classical control measures have led to the search for alternative approaches to minimize the use of antibiotics by selecting naturally resistant animals. Polymorphisms in genes associated with the innate immune system are strong candidates to be evaluated as genetic markers. In this work, we evaluated a set of single nucleotidepolymorphisms (SNPs) in candidate genes for health and production traits, and determined their association with the somatic cell score (SCS) as an indicator of mastitis in Argentinean dairy cattle. We evaluated 941 cows: Holstein (n = 677) and Holstein × Jersey (n = 264) crossbred, daughters from 22 bulls from 14 dairy farms located in the central dairy area of Argentina. Two of the 21 successfully genotyped markers were found to be significantly associated (p < 0.05) with the SCS: GHR_140 and OPN_8514C-T. The heterozygote genotype for GHR_140 showed a favorable effect in reducing the SCS. On the other hand, heterozygote genotypes for OPN8514C-T caused an increase in the SCS; moreover, combined genotypes for OPN SNPs showed an even larger effect. These findings can contribute to the design of effective marker-assisted selection programs. PMID:25783851

The objective of this study is to identify single-nucleotidepolymorphisms (SNPs) predictors of treatment nonresponse to the first anti-TNF-alpha agent in ankylosing spondylitis (AS). Patients were classified as "nonresponders" if they failed to achieve improvement ≥50 % of the initial BASDAI. We selected candidate SNPs previously reported, associated with susceptibility or pathogenesis of AS and with other spondylarthropaties (SpAs). The predictors of nonresponse were modeled with multiple logistic regression. The predictive power of the genetic model of nonresponse to treatment was tested with AUC-ROC. One hundred and twenty-one (121) AS patients fulfilled the inclusion criteria. Of the candidate SNPs tested for association with treatment effectiveness, five independent predictors were identified: rs917997, rs755622, rs1800896, rs3740691, and rs1061622. The genetic model of nonresponse to treatment had a predictive power of 0.77 (95 % CI 0.68-0.86). Our study identified several polymorphisms which could be the useful genetic biomarkers in predicting nonresponse to anti-TNF-alpha therapy. PMID:24337767

The lack of a sufficiently discriminatory molecular subtyping tool for Salmonella enterica serovar Enteritidis has hindered source attribution efforts and impeded regulatory actions required to disrupt its food-borne transmission. The underlying biological reason for the ineffectiveness of current molecular subtyping tools such as pulsed-field gel electrophoresis (PFGE) and phage typing appears to be related to the high degree of clonality of S. Enteritidis. By interrogating the organism's genome, we previously identified single nucleotidepolymorphisms (SNP) distributed throughout the chromosome and have designed a highly discriminatory PCR-based SNP typing test based on 60 polymorphic loci. The application of the SNP-PCR method to DNA samples from S. Enteritidis strains (n = 55) obtained from a variety of sources has led to the differentiation and clustering of the S. Enteritidis isolates into 12 clades made up of 2 to 9 isolates per clade. Significantly, the SNP-PCR assay was able to further differentiate predominant PFGE types (e.g., XAI.0003) and phage types (e.g., phage type 8) into smaller subsets. The SNP-PCR subtyping test proved to be an accurate, precise, and quantitative tool for evaluating the relationships among the S. Enteritidis isolates tested in this study and should prove useful for clustering related S. Enteritidis isolates involved in outbreaks. PMID:25297333

The lack of a sufficiently discriminatory molecular subtyping tool for Salmonella enterica serovar Enteritidis has hindered source attribution efforts and impeded regulatory actions required to disrupt its food-borne transmission. The underlying biological reason for the ineffectiveness of current molecular subtyping tools such as pulsed-field gel electrophoresis (PFGE) and phage typing appears to be related to the high degree of clonality of S. Enteritidis. By interrogating the organism's genome, we previously identified single nucleotidepolymorphisms (SNP) distributed throughout the chromosome and have designed a highly discriminatory PCR-based SNP typing test based on 60 polymorphic loci. The application of the SNP-PCR method to DNA samples from S. Enteritidis strains (n = 55) obtained from a variety of sources has led to the differentiation and clustering of the S. Enteritidis isolates into 12 clades made up of 2 to 9 isolates per clade. Significantly, the SNP-PCR assay was able to further differentiate predominant PFGE types (e.g., XAI.0003) and phage types (e.g., phage type 8) into smaller subsets. The SNP-PCR subtyping test proved to be an accurate, precise, and quantitative tool for evaluating the relationships among the S. Enteritidis isolates tested in this study and should prove useful for clustering related S. Enteritidis isolates involved in outbreaks. PMID:25297333

While Simple Sequence Repeats (SSRs) are extremely useful genetic markers, recent advances in technology have produced a shift toward use of single nucleotidepolymorphisms (SNPs). The different mutational properties of these two classes of markers result in differences in heterozygosities and allele frequencies that may have implications for their use in assessing relatedness and evaluation of genetic diversity. We compared analyses based on 89 SSRs (primarily dinucleotide repeats) to analyses based on 847 SNPs in individuals from the same 259 inbred maize lines, which had been chosen to represent the diversity available among current and historic lines used in breeding. The SSRs performed better at clustering germplasm into populations than did a set of 847 SNPs or 554 SNP haplotypes, and SSRs provided more resolution in measuring genetic distance based on allele-sharing. Except for closely related pairs of individuals, measures of distance based on SSRs were only weakly correlated with measures of distance based on SNPs. Our results suggest that 1) large numbers of SNP loci will be required to replace highly polymorphic SSRs in studies of diversity and relatedness and 2) relatedness among highly-diverged maize lines is difficult to measure accurately regardless of the marker system. PMID:18159250

The akirin 2 gene, located on chromosome 9 in cattle, was previously reported to be associated with nuclear factor-kappa B (NF-κB), involved in immune reactions and marbling of meat. To determine whether a single nucleotidepolymorphism (SNP) in akirin 2 is associated with economically important traits of Korean native cattle, the c.*188G>A SNP DNA marker in the 3'-UTR region of akirin 2 was analyzed for its association with carcass weight, longissimus muscle area and marbling. The c.*188G>A SNP was genotyped by polymerase chain reaction restriction fragment length polymorphism, and the frequency of the AA, AG, and GG genotypes were 6.82%, 71.29% and 21.88% respectively. This SNP was significantly associated with longissimus muscle area (Bonferroni corrected P A SNP of akirin 2 might be useful as a DNA marker for longissimus muscle area and marbling scores in Korean native cattle. PMID:23718263

The growth hormone gene ( GH) affects animal growth and is a potential target for genetic studies of variation related to growth traits. In this study, we analyzed single nucleotidepolymorphisms (SNPs) in GH intron regions and their associations with growth traits in large yellow croaker, Larimichthys crocea, from Zhejiang and Fujian stocks. The results of PCR-single strand conformation polymorphism showed two haplotypes of intron 1, named AA and AB genotypes, in Zhejiang stock. AB exhibited an SNP at position 196 (G→A) that was negatively correlated with body height and positively correlated with standard length/body height ( P≤0.05). Two different genotypes, CC and CD, were identified in intron 2 in Fujian stock, with CD showing an SNP at position 692 (T→C). The CD genotype had a significantly positive correlation with both weight and total length ( P≤0.01). These basic data highlight the potential for using GH as a genetic marker of fish growth in marker assisted selection.

Irritable bowel syndrome (IBS) is a common functional disorder with distinct features of stress-related pathophysiology. A key mediator of the stress response is corticotropin-releasing hormone (CRH). Although some candidate genes have been identified in stress-related disorders, few studies have examined CRH-related gene polymorphisms. Therefore, we tested our hypothesis that single-nucleotidepolymorphisms (SNPs) in CRH-related genes influence the features of IBS. Methods: In total, 253 individuals (123 men and 130 women) participated in this study. They comprised 111 IBS individuals and 142 healthy controls. The SNP genotypes in CRH (rs28364015 and rs6472258) and CRH-binding protein (CRH-BP) (rs10474485) were determined by direct sequencing and real-time polymerase chain reaction. The emotional states of the subjects were evaluated using the State-Trait Anxiety Inventory, Perceived Stress Scale, and the Self-rating Depression Scale. Results: Direct sequencing of the rs28364015 SNP of CRH revealed no genetic variation among the study subjects. There was no difference in the genotype distributions and allele frequencies of rs6472258 and rs10474485 between IBS individuals and controls. However, IBS subjects with diarrhea symptoms without the rs10474485 A allele showed a significantly higher emotional state score than carriers. Conclusions: These results suggest that the CRH and CRH-BP genes have no direct effect on IBS status. However, the CRH-BP SNP rs10474485 has some effect on IBS-related emotional abnormalities and resistance to psychosocial stress. PMID:26882083

Fire blight has spread from North America to New Zealand, Europe, and the Mediterranean region. We were able to differentiate strains from various origins with a novel PCR method. Three Single NucleotidePolymorphisms (SNPs) in the Erwinia amylovora genome were characteristic of isolates from North America and could distinguish them from isolates from other parts of the world. They were derived from the galE, acrB, and hrpA genes of strains Ea273 and Ea1/79. These genes were analyzed by conventional PCR (cPCR) and quantitative PCR (qPCR) with differential primer annealing temperatures. North-American E. amylovora strains were further differentiated according to their production of L: -2,5-dihydrophenylalanine (DHP) as tested by growth inhibition of the yeast Rhodotorula glutinis. E. amylovora fruit tree (Maloideae) and raspberry (rubus) strains were also differentiated by Single Strand Conformational Polymorphism analysis. Strains from the related species Erwinia pyrifoliae isolated in Korea and Japan were all DHP positive, but were differentiated from each other by SNPs in the galE gene. Differential PCR is a rapid and simple method to distinguish E. amylovora as well as E. pyrifoliae strains according to their geographical origin. PMID:22538467

Lactose intolerance in northern Europeans is strongly associated with a single-nucleotidepolymorphism (SNP) located 14 kb upstream of the human lactase gene: -13,910 C/T. We examined whether SNPs in the 5' flanking region of the pig lactase gene are similar to those in the human gene and whether these polymorphisms play a functional role in regulating pig lactase gene expression. The 5' flanking region of the lactase gene from several different breeds of pigs was cloned and analyzed for gene regulatory activity of a luciferase reporter gene. One SNP was found in the enhancer region (-797 G/A) and two were found in the promoter region (-308G/C and -301 A/G). The promoter C-308,G-301(Pro-CG) strongly promotes the expression of the lactase gene, but the promoter G-308,A-301(Pro-GA) does not. The enhancer A-797(Enh-A) genotype for Pro-GA can significantly enhance promoter activity, but has an inhibitory effect on Pro-CG. The Enhancer G-797(Enh-G) has a significant inhibitory effect on both promoters. In conclusion, the order of effectiveness on the pig lactase gene is Enh-A+Pro-GA>Enh-A/G+Pro-CG>Enh-G+Pro-GA. PMID:24809963

Myostatin (MSTN) is a negative modulator of muscle mass. We characterized the horse (Equus caballus) MSTN gene and identified and analysed single nucleotidepolymorphisms (SNPs) in breeds of different morphological types. Sequencing of coding, untranslated, intronic, and regulatory regions of MSTN gene in 12 horses from 10 breeds revealed seven SNPs: two in the promoter, four in intron 1, and one in intron 2. The SNPs of the promoter (GQ183900:g.26T>C and GQ183900:g.156T>C, the latter located within a conserved TATA-box like motif) were screened in 396 horses from 16 breeds. The g.26C and the g.156C alleles presented higher frequency in heavy (brachymorphic type) than in light breeds (dolichomorphic type such as Italian Trotter breed). The significant difference of allele frequencies for the SNPs at the promoter and analysis of molecular variance (AMOVA) on haplotypes indicates that these polymorphisms could be associated with variability of morphology traits in horse breeds. PMID:20706663

Feed efficiency and growth are the most important traits in pig production, and very few genetic markers have been reported to be associated with feed efficiency. The suppressor of cytokine signalling-2 (encoded by SOCS2) is the main negative regulator of somatic growth, and the knockout of SOCS2 and naturally mutant mice have high-growth phenotypes. Porcine SOCS2 was selected as a primary positional candidate for feed efficiency, because it is located on chromosome 5q, in the vicinity of a Quantitative Trait Locus (QTL) region for food conversion ratio in pigs. Here, we report five single nucleotidepolymorphisms identified by sequencing of the promoter region and exon 1. One PCR-RFLP assay was designed for genotyping the polymorphism c.1667A > G (GenBank Accession No AY312266). Association analyses were performed in an Australian mapping resource pedigree population (PRDC-US43) for food conversion ratio, backfat, IGF1 level and growth traits and showed significant effects on average daily gain on test (ADG2) (P

Recurrent aphthous stomatitis (RAS) is a common painful, ulcerative oral inflammatory disorder with unknown aetiology. Immune system and aberrant cytokine cascade deemed to be critical in outbreaks of RAS ulcers. Interleukin-1 (IL-1) and IL-6 are the most potent pro-inflammatory cytokines. Single nucleotidepolymorphisms (SNPs) of IL-1 and IL-6 genes can affect the secretion of these cytokines. The aim of this study was to investigate the association between RAS and IL-6 and IL-1 in Iranian subjects with minor RAS. Genomic DNA was obtained from 64 Iranian patients with RAS. IL-1α C -889 T, IL-1β C -511 T, IL-1β C +3962 T, IL-1R C pst-I 1970 T, IL-1Ra C Mspa-I11100 T, IL-6 C -174 G and IL-6 A nt +565 G polymorphisms were determined using polymerase chain reaction with sequence-specific primers (PCR-SSP). The frequency of C -174 C genotype in the patients group was significantly different from the healthy control. No other significant differences were found in genotype and alleles frequencies between the two groups. These results indicate that certain SNPs of IL-6 gene at position -174 which located in promoter have association with predisposition of individuals to RAS. PMID:26385127

Growth traits represent a main goal in aquaculture breeding programs and may be related to adaptive variation in wild fisheries. Integrating quantitative trait loci (QTL) mapping and next generation sequencing can greatly help to identify variation in candidate genes, which can result in marker-assisted selection and better genetic structure information. Turbot is a commercially important flatfish in Europe and China, with available genomic information on QTLs and genome mapping. Muscle and liver RNA-seq from 18 individuals was carried out to obtain gene sequences and markers functionally related to growth, resulting in a total of 20,447 genes and 85,344 single nucleotidepolymorphisms (SNPs). Many growth-related genes and SNPs were identified and placed in the turbot genome and genetic map to explore their co-localization with growth-QTL markers. Forty-five SNPs on growth-related genes were selected based on QTL co-localization and relevant function for growth traits. Forty-three SNPs were technically feasible and validated in a wild Atlantic population, where 91% were polymorphic. The integration of functional and structural genomic resources in turbot provides a practical approach for QTL mining in this species. Validated SNPs represent a useful set of growth-related gene markers for future association, functional and population studies in this flatfish species. PMID:26901189

Paraoxonase-1 (PON1) and butyrylcholinesterase (BCHE) are natural bioscavengers of organophosphate acetylcholinesterase inhibitors in the human body, which can determine individual sensitivity to organophosphate toxicity. Interindividual differences in activity of PON1 (catalytic bioscavenger) and substrate specificity are strongly associated with the substitution of two amino acids: Leu/Met (L/M) at position 55 (rs854560) and Gln/Arg (Q/R) at position 192 (rs662). In the case of BCHE (stoichiometric bioscavenger) substitution, Ala/Thr (A/T) at position 539 produces the so-called "K-variant" of the enzyme (rs1803274). Threonine allele is often co-inherited with an atypical BCHE allele (rs1799807). The atypical variant of BCHE displays a lower affinity for cholinesterase inhibitors. Genotyping rs662 and rs1803274 single-nucleotidepolymorphisms (SNP) by high-resolution melting (HRM) is facilitated by the nucleotide substitution A>G (G>A), which resulted in a changed number of hydrogen bonds in the PCR product and, consequently, shifted T m. In the case of rs854560, genotyping is complicated by the nucleotide substitution T>A, which has no significant effect on the T m of the PCR product. An addition of a small quantity of LL homozygote DNA into the reaction mixture before PCR discriminates the three genotypes by the melt curves due to different amounts of heteroduplexes formed in the LM and MM samples. HRM analysis can be applied for genotyping human rs854560, rs662, and rs1803274 SNPs. PMID:24705954

BACKGROUND Hypertension is a major global health burden, but, although systolic and diastolic blood pressure (BP) each have estimated heritability of at least 30%, <3% of their variance has been attributed to particular genetic variants. Few studies have shown interactions between pairs of single nucleotidepolymorphisms (SNPs) to be associated with BP. Although many studies use a Bonferroni correction for multiple testing to control type I error, thereby potentially reducing power, false discovery rate (FDR) approaches are also used in genome-wide studies. Renal ion balance genes have been associated with BP regulation, but, although inflammation has been studied in connection with BP, few studies have reported associations between inflammation genes and BP. METHODS We analyzed SNP-SNP interactions among 31 SNPs from genes involved in renal ion balance and 30 SNPs from genes involved in inflammation using data from the Framingham Heart Study. RESULTS No evidence of association was found for interactions among renal ion balance SNPs for either systolic or diastolic BP. A group of 3 interactions involving 6 inflammation genes (IKBKB–NFKBIA, IKBKE–CHUK, and ADIPOR2–RETN) showed evidence of association with diastolic BP with an FDR of 4.2%; no single interaction reached experiment-wide significance. CONCLUSIONS This study identified promising and biologically plausible candidates for interactions between inflammation genes that may be associated with DBP. Analysis using the FDR may allow detection of signals in the presence of modest noise (false positives) that a stringent approach based on Bonferroni-corrected P value thresholds may miss. PMID:25063733

Genotyping arrays are tools for high-throughput genotyping, which is beneficial in constructing saturated genetic maps and therefore high-resolution mapping of complex traits. Since the report of the first cucumber genome draft, genetic maps have been constructed mainly based on simple-sequence repeats (SSRs) or on combinations of SSRs and sequence-related amplified polymorphism (SRAP). In this study, we developed the first cucumber genotyping array consisting of 32,864 single-nucleotidepolymorphisms (SNPs). These markers cover the cucumber genome with a median interval of ~2 Kb and have expected genotype calls in parents/F1 hybridizations as a training set. The training set was validated with Fluidigm technology and showed 96% concordance with the genotype calls in the parents/F1 hybridizations. Application of the genotyping array was illustrated by constructing a 598.7 cM genetic map based on a '9930' × 'Gy14' recombinant inbred line (RIL) population comprised of 11,156 SNPs. Marker collinearity between the genetic map and reference genomes of the two parents was estimated at R2 = 0.97. We also used the array-derived genetic map to investigate chromosomal rearrangements, regional recombination rate, and specific regions with segregation distortions. Finally, 82% of the linkage-map bins were polymorphic in other cucumber variants, suggesting that the array can be applied for genotyping in other lines. The genotyping array presented here, together with the genotype calls of the parents/F1 hybridizations as a training set, should be a powerful tool in future studies with high-throughput cucumber genotyping. An ultrahigh-density linkage map constructed by this genotyping array on RIL population may be invaluable for assembly improvement, and for mapping important cucumber QTLs. PMID:25874931

Background Infection with HIV-1 may result in severe cognitive and motor impairment, referred to as HIV-1-associated dementia (HAD). While its prevalence has dropped significantly in the era of combination antiretroviral therapy, milder neurocognitive disorders persist with a high prevalence. To identify additional therapeutic targets for treating HIV-associated neurocognitive disorders, several candidate gene polymorphisms have been evaluated, but few have been replicated across multiple studies. Methods We here tested 7 candidate gene polymorphisms for association with HAD in a case-control study consisting of 86 HAD cases and 246 non-HAD AIDS patients as controls. Since infected monocytes and macrophages are thought to play an important role in the infection of the brain, 5 recently identified single nucleotidepolymorphisms (SNPs) affecting HIV-1 replication in macrophages in vitro were also tested. Results The CCR5 wt/Δ32 genotype was only associated with HAD in individuals who developed AIDS prior to 1991, in agreement with the observed fading effect of this genotype on viral load set point. A significant difference in genotype distribution among all cases and controls irrespective of year of AIDS diagnosis was found only for a SNP in candidate gene PREP1 (p = 1.2×10−5). Prep1 has recently been identified as a transcription factor preferentially binding the −2,518 G allele in the promoter of the gene encoding MCP-1, a protein with a well established role in the etiology of HAD. Conclusion These results support previous findings suggesting an important role for MCP-1 in the onset of HIV-1-associated neurocognitive disorders. PMID:22347417

Genotyping arrays are tools for high-throughput genotyping, which is beneficial in constructing saturated genetic maps and therefore high-resolution mapping of complex traits. Since the report of the first cucumber genome draft, genetic maps have been constructed mainly based on simple-sequence repeats (SSRs) or on combinations of SSRs and sequence-related amplified polymorphism (SRAP). In this study, we developed the first cucumber genotyping array consisting of 32,864 single-nucleotidepolymorphisms (SNPs). These markers cover the cucumber genome with a median interval of ~2 Kb and have expected genotype calls in parents/F1 hybridizations as a training set. The training set was validated with Fluidigm technology and showed 96% concordance with the genotype calls in the parents/F1 hybridizations. Application of the genotyping array was illustrated by constructing a 598.7 cM genetic map based on a ‘9930’ × ‘Gy14’ recombinant inbred line (RIL) population comprised of 11,156 SNPs. Marker collinearity between the genetic map and reference genomes of the two parents was estimated at R2 = 0.97. We also used the array-derived genetic map to investigate chromosomal rearrangements, regional recombination rate, and specific regions with segregation distortions. Finally, 82% of the linkage-map bins were polymorphic in other cucumber variants, suggesting that the array can be applied for genotyping in other lines. The genotyping array presented here, together with the genotype calls of the parents/F1 hybridizations as a training set, should be a powerful tool in future studies with high-throughput cucumber genotyping. An ultrahigh-density linkage map constructed by this genotyping array on RIL population may be invaluable for assembly improvement, and for mapping important cucumber QTLs. PMID:25874931

Genetic variation in DNA repair genes can modulate DNA repair capacity and may be related to the risk of cancer. The human papillomavirus is considered to be a necessary but not sufficient cause for cervical cancer and, therefore, other factors contribute to the carcinogenesis. A hereditary component for this neoplasia has been reported. Evaluation of the association of six polymorphisms was carried out in the following DNA repair genes: XRCC1 (Arg194Trp, Arg280His, and Arg399Gln), ERCC1 (Asp118Asp), ERCC2 (Lys751Gln), and ERCC4 (Arg415Gln). The cases (n=110) included 65 squamous cell carcinomas (SCCs) and 45 squamous intraepithelial lesions (SIL). Controls (n=68) were recruited from among women without cervical abnormalities. Genotypes were determined by PCR-restriction fragment length polymorphism and DNA sequencing. A positive association was observed between the polymorphisms of XRCC1 genes, that is, in codons 194 [P=0.001, odds ratio (OR)=20.1, 95% confidence interval (CI)=5.9-68.8], 280 (P=0.001, OR=5.4, 95% CI=2.3-12.6), and 399 (P=0.008, OR=4.2, 95% CI=1.5-12.1) and cervical cancer. SIL patients also showed a significant association with codon 194 (P=0.012, OR=3.8, 95% CI=1.3-10.6), but not with 280 (P=0.35) and 399 (P=0.81). A positive correlation was also found in ERCC4 Gln415Gln in both SCCs and SILs (P=0.001, OR=21.3, 95% CI=7.1-64.0 and P=0.001, OR=7.8, 95% CI=2.9-20.9, respectively). For ERCC2 Gln751Gln, the association was significant for both SCCs (P=0.001, OR=10.1, 95% CI=2.6-37.9) and SILs (P=0.001, OR=8.9, 95% CI=2.8-28.3). However, the risk of SCC did not appear to differ significantly among individuals with the ERCC1 Asp118Asp genotype (P=0.404). For SILs, it appeared to be a protective genotype (95% CI=0.1-0.7). This study indicates that variant types of DNA repair genes play an important role in modifying individual susceptibility to SCC. PMID:25812040

Three NOD2 polymorphisms (single nucleotidepolymorphism [SNP]8 [2104C>T, Arg702Trp], SNP12 [2722G>C, Gly908Arg], and SNP13 [3020insC, Leu1007 fsins C]), identified as disease-associated variants in Crohn's disease, have recently been suggested as gene markers of the outcome of hematopoietic stem cell transplantation (HSCT). In the present multicenter study of 464 donor-recipient pairs, we focused on the effect of NOD2 mutation(s) on the risk of infections and acute graft-versus-host disease (aGVHD). The presence of SNP13 in recipients, donors, or both was more frequently seen in patients having sepsis than in those lacking sepsis (9 of 48 versus 33 of 386, P = .046). The presence of SNP8 (recipient and/or donor positive) was associated with a higher rate of Herpes viruses reactivation (17 of 21 versus 86 of 173, P = .007). In the SNP8-positive group, a trend for a higher rate of bacteremia well controlled by antibiotics was found (9 of 10 versus 47 of 81, P = .106). In contrast, the presence of SNP13 in recipient and/or donor resulted in a poor response to antibiotics (5 of 11 versus 9 of 10, P = .042). A statistically significant association between the presence of NOD2 SNPs and acute grade > II GVHD was found in a subgroup of HSCT patients who received transplants from unrelated donors with a myeloablative conditioning regimen that included antithymocyte globulin (ATG). In this subgroup of patients, donor positivity for any SNPs investigated (7 of 18 versus 17 of 113, P = .036) and, independently, only the presence of SNP8 (4 of 8 versus 20 of 123, P = .055) were associated with severe grade ≥ II aGVHD. In conclusion, SNP8 positivity in donors or recipients makes patients more prone to Herpes viruses reactivation and bacteremia but not to sepsis. Septic complications were associated with SNP13 polymorphism. SNP8 in donors constitutes a risk factor of severe aGVHD, but only if patients received transplants from unrelated donors and received ATG as part of a

The control of onchocerciasis or river blindness by mass treatment of the population with ivermectin (IVM) has been a great success until now, so that in certain foci its elimination has become feasible. However, after more than 20 years of repeated IVM mass treatment, the disease still persists in many endemic countries. Sub-optimal responses and genetic changes have been reported in Onchocerca volvulus populations under high IVM pressure but more work is needed to determine whether resistance is developing. The situation needs to be urgently clarified to preserve the achievements of onchocerciasis control programs. In this study, O. volvulus adult worms were collected from the same individuals, before IVM exposure and following three years of annual or three-monthly treatments at 150 μg/kg or 800 μg/kg. Four single nucleotidepolymorphisms (SNPs) occurring in the β-tubulin gene of these parasites were investigated. We found changes in genotype frequencies in O. volvulus β-tubulin gene associated with IVM treatments. The SNP at position 1545 (A/G) showed a significant increase in frequency of the less common nucleotide in the female worms following treatment. After 13 three-monthly treatments, female worm homozygotes with the less common genotype, prior to treatment, increased in frequency. The selected homozygotes, as well as heterozygotes, appeared to be less fertile (without or with very few embryonic stages in their uteri) than the wild-type homozygotes. These results provide additional evidence for genetic selection and strengthen the warning that selection for IVM resistance may be occurring in some O. volvulus populations. PMID:22677339

Feline infectious peritonitis (FIP) is an immune-mediated, highly lethal disease caused by feline coronavirus (FCoV) infection. Currently, no protective vaccine or effective treatment for the disease is available. Studies have found that some cats survive the challenge of virulent FCoV isolates. Since cellular immunity is thought to be critical in preventing FIP and because diseased cats often show a significant decrease in interferon-γ (IFN-γ) production, we investigated whether single nucleotidepolymorphisms (SNP) in the feline IFN-γ gene (fIFNG) are associated with the outcome of infection. A total of 82 asymptomatic and 63 FIP cats were analyzed, and 16 SNP were identified in intron 1 of fIFNG. Among these SNP, the fFING + 428 T allele was shown to be a FIP-resistant allele (p = 0.03), and the heterozygous genotypes 01C/T and +408C/T were found to be FIP-susceptible factors (p = 0.004). Furthermore, an fIFNG + 428 resistant allele also showed a clear correlation with the plasma level of IFN-γ in FIP cats. For the identification of these three FIP-related SNP, genotyping methods were established using amplification refractory mutation system PCR (ARMS-PCR) and restriction fragment length polymorphisms (RFLP), and the different genotypes could easily be identified without sequencing. The identification of additional FIP-related SNP will allow the selection of resistant cats and decrease the morbidity of the cat population to FIP. PMID:24886103

Pomegranate is a valuable crop that is grown commercially in many parts of the world. Wild species have been reported from India, Turkmenistan and Socotra. Pomegranate fruit has a variety of health-beneficial qualities. However, despite this crop's importance, only moderate effort has been invested in studying its biochemical or physiological properties or in establishing genomic and genetic infrastructures. In this study, we reconstructed a transcriptome from two phenotypically different accessions using 454-GS-FLX Titanium technology. These data were used to explore the functional annotation of 45,187 fully annotated contigs. We further compiled a genetic-variation resource of 7,155 simple-sequence repeats (SSRs) and 6,500 single-nucleotidepolymorphisms (SNPs). A subset of 480 SNPs was sampled to investigate the genetic structure of the broad pomegranate germplasm collection at the Agricultural Research Organization (ARO), which includes accessions from different geographical areas worldwide. This subset of SNPs was found to be polymorphic, with 10.7% loci with minor allele frequencies of (MAF<0.05). These SNPs were successfully used to classify the ARO pomegranate collection into two major groups of accessions: one from India, China and Iran, composed of mainly unknown country origin and which was more of an admixture than the other major group, composed of accessions mainly from the Mediterranean basin, Central Asia and California. This study establishes a high-throughput transcriptome and genetic-marker infrastructure. Moreover, it sheds new light on the genetic interrelations between pomegranate species worldwide and more accurately defines their genetic nature. PMID:24558460

Pomegranate is a valuable crop that is grown commercially in many parts of the world. Wild species have been reported from India, Turkmenistan and Socotra. Pomegranate fruit has a variety of health-beneficial qualities. However, despite this crop's importance, only moderate effort has been invested in studying its biochemical or physiological properties or in establishing genomic and genetic infrastructures. In this study, we reconstructed a transcriptome from two phenotypically different accessions using 454-GS-FLX Titanium technology. These data were used to explore the functional annotation of 45,187 fully annotated contigs. We further compiled a genetic-variation resource of 7,155 simple-sequence repeats (SSRs) and 6,500 single-nucleotidepolymorphisms (SNPs). A subset of 480 SNPs was sampled to investigate the genetic structure of the broad pomegranate germplasm collection at the Agricultural Research Organization (ARO), which includes accessions from different geographical areas worldwide. This subset of SNPs was found to be polymorphic, with 10.7% loci with minor allele frequencies of (MAF<0.05). These SNPs were successfully used to classify the ARO pomegranate collection into two major groups of accessions: one from India, China and Iran, composed of mainly unknown country origin and which was more of an admixture than the other major group, composed of accessions mainly from the Mediterranean basin, Central Asia and California. This study establishes a high-throughput transcriptome and genetic-marker infrastructure. Moreover, it sheds new light on the genetic interrelations between pomegranate species worldwide and more accurately defines their genetic nature. PMID:24558460

Aim Elevated levels of sterol regulatory element-binding protein-1 (SREBP-1) have been found in endometrial cancer (EC), suggesting that it is essential to the development of EC. Obesity and diabetes have been established as known risk factors of EC, while SREBF-1 gene polymorphisms have also been found to be associated with obesity and type II diabetes. Therefore, we hypothesize that single nucleotidepolymorphism (SNP) in SREBF-1 gene may be associated with increased risk of EC. Method We analyzed the sequence of SREBF-1 in tissue samples from 30 EC cases and 6 benign controls using high throughput method. Based on the primary results, we selected one SNP (rs2297508) as a genetic marker to conduct a hospital-based case-control study with 139 EC cases and 129 benign controls. The samples were examined under the microscope to determine their histopathology prior to the SNP analysis using RT-PCR. Results Through sequence analysis, we found 10 SNPs of SREBF-1 associated with EC, including 3 new SNPs. Fourteen percent of EC showed the rs2297508 SNP with C allele, while only 7% had the C allele was present in benign controls (p = 0.027, OR = 1.983). Additionally, the C allele was associated with cancer differentiation (p<0.05) and the depth of myometrial invasion (p<0.05). Conclusion Our study indicates that SNP (rs2297508) of SREBF-1 may serve as a genetic predisposition factor for the development of EC and screening of such genetic marker may be helpful in its early detection. PMID:24614076

Genomic methodologies applied in evolutionary and fisheries research have been of great benefit to understand the marine ecosystem and the management of natural resources. Although single nucleotidepolymorphisms (SNPs) are attractive for the study of local adaptation, spatial stock management and traceability, and investigating the effects of fisheries-induced selection, they have rarely been exploited in non-model organisms. This is partly due to difficulties in finding and validating SNPs in species with limited or no genomic resources. Complementary to random genome-scan approaches, a targeted candidate gene approach has the potential to unveil pre-selected functional diversity and provides more in depth information on the action of selection at specific genes. For example genes can be under selective pressure due to climate change and sustained periods of heavy fishing pressure. In this study, we applied a candidate gene approach in sole (Solea solea L.), an important member of the demersal ecosystem. As consumption flatfish it is heavy exploited and has experienced associated life-history changes over the last 60years. To discover novel genetic polymorphisms in or around genes linked to important life history traits in sole, we screened a total of 76 candidate genes related to growth and maturation using a targeted resequencing approach. We identified in total 86 putative SNPs in 22 genes and validated 29 SNPs using a multiplex single-base extension genotyping assay. We found 22 informative SNPs, of which two represent non-synonymous mutations, potentially of functional relevance. These novel markers should be rapidly and broadly applicable in analyses of natural sole populations, as a measure of the evolutionary signature of overfishing and for initiatives on marker assisted selection. PMID:23067785

There is significant variability in individual responses to opioid drugs, which is likely to have a significant genetic component. A number of non-synonymous single-nucleotidepolymorphisms (SNPs) in the coding regions of the μ-opioid receptor gene (OPRM1) have been postulated to contribute to this variability. Although many studies have investigated the clinical influences of these μ-opioid receptor variants, the outcomes are reported in the context of thousands of other genes and environmental factors, and we are no closer to being able to predict individual response to opioids based on genotype. Investigation of how μ-opioid receptor SNPs affect their expression, coupling to second messengers, desensitization and regulation is necessary to understand how subtle changes in receptor structure can impact individual responses to opioids. To date, the few functional studies that have investigated the consequences of SNPs on the signalling profile of the μ-opioid receptor in vitro have shown that the common N40D variant has altered functional responses to some opioids, while other, rarer, variants display altered signalling or agonist-dependent regulation. Here, we review the data available on the effects of μ-opioid receptor polymorphisms on receptor function, expression and regulation in vitro, and discuss the limitations of the studies to date. Whether or not μ-opioid receptor SNPs contribute to individual variability in opioid responses remains an open question, in large part because we have relatively little good data about how the amino acid changes affect μ-opioid receptor function. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2 PMID:24527749

Ischemia-reperfusion injury due to hypoxia/reoxygenation (H/R) is one of the main causes of liver damage during liver surgery. Donor interleukin-6 (IL-6) rs1800796 single nucleotidepolymorphisms (SNPs) affect the metabolism of tacrolimus following liver transplantation-related hepatic H/R. This study investigated the response of IL-6 and its promoter polymorphisms to hepatic H/R in liver parenchymal cells. The association between IL-6 rs1800796 SNPs and IL-6 expression was measured in 84 disease-free liver tissues using tissue microarrays and immunohistochemistry. Subsequently, LO2G, LO2C and NC-LO2 cells were successfully constructed via stable lentivirus-mediated transfection. The effects of IL-6 and its SNPs on the biological function of LO2 cells were examined using a cell model of H/R. Our results revealed that IL-6 was mainly expressed in hepatocytes. The intermediate IL-6 expression rate in genotype CC carriers was higher than that in genotype CG/GG carriers (P=0.006), which was subsequently verified at the IL-6 mRNA level (P=0.002). The concentrations of alanine aminotransferase in the LO2G cells were significantly higher than those in the LO2C cells following H/R for 6 h and H/R for 24 h (P<0.05). The viability of the LO2C cells was higher than that of the LO2G cells (P<0.05). Furthermore, the expression of IL-6 and its downstream molecules was significantly increased in the LO2C cells compared with the LO2G cells (P<0.05). Therefore, the sequence variants of rs1800796 SNPs (G→C) exhibit an increased IL-6 transcription efficiency in liver parenchymal cells. In addition, the increased expression of IL-6 protects the hepatocytes following hepatic H/R injury. PMID:27221654

Background Marbling defined by the amount and distribution of intramuscular fat, so-called Shimofuri, is an economically important trait of beef cattle in Japan. The c17-25 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low-marbled and high-marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the akirin 2 (AKIRIN2) gene containing the c17-25 EST sequence was considered as a positional functional candidate for the gene responsible for marbling. In this study, we explored single nucleotidepolymorphism (SNP) in the AKIRIN2 and analyzed association of the SNP with marbling. Findings A SNP in the 3' untranslated region of the AKIRIN2, referred to as c.*188G>A, was the only difference detected between high- and low-marbled steer groups. The SNP was associated with marbling in 3 experiments using 100 sires (P = 0.041), 753 paternal half-sib progeny steers from 4 sires heterozygous for the c.*188G>A (P = 0.005), and 730 paternal half-sib progeny steers from 3 sires homozygous for the A allele at the c.*188G>A (P = 0.047), in Japanese Black beef cattle. The effect of genotypes of the SNP on subcutaneous fat thickness was not statistically significant (P > 0.05). Conclusion These findings suggest that the AKIRIN2 SNP polymorphism is associated with marbling and may be useful for effective marker-assisted selection to increase the levels of marbling in Japanese Black beef cattle. PMID:19594944

BACKGROUND The aim of this study was to examine the associations between the single-nucleotidepolymorphisms (SNPs) of interleukin-17 (IL-17), including rs763780 (7488A/G), rs2275913 (-197G/A), and rs8193036 (-737C/T), and asthma susceptibility in an Asian population. MATERIAL AND METHODS From Oct 2013 to Dec 2014, 125 asthma patients enrolled in our hospital were selected as the case group. Another 132 healthy controls undergoing physical examinations in our hospital were enrolled as the control group. The genotype frequencies of IL-17 rs763780, rs2275913 and rs8193036 SNPs were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Comprehensive Meta-analysis 2.0 (CMA 2.0) software was applied for meta-analysis. RESULTS Our results demonstrated that asthma patients presented with higher frequencies of GA genotype in rs2275913 and TT genotype in rs8193036 of IL-17 than healthy controls (both P<0.001). The genotype frequencies of IL-17 rs763780 between the asthma patients and healthy controls exhibited no significant differences (P>0.05). The comparisons on the rs2275913 and rs8193036 frequencies between the asthma patients and healthy controls were statistically significant in both allele and addictive models (all P<0.05). The frequency of IL-17 rs763780 between the asthma patients and healthy controls were statistically different in allele models (P<0.05), but not in addictive models (P>0.05). The overall results of our case-control study were further confirmed by meta-analysis. CONCLUSIONS Our results revealed that, in an Asian population, IL-17 rs763780, rs2275913, and rs8193036 SNPs may be associated with asthma susceptibility, and GA genotype in rs2275913 and TT genotype in rs8193036 of IL-17 may contribute to increased risk of asthma in Asians. PMID:26954344

Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD, and simple sequence repeat (SSR) markers. This study was carried out to assess the utility of single nucleotidepolymorphism (SNP) markers generated from 3′ untranslated regions (UTR) for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars, and old cultivars imported from different parts of the world were screened with seven SSR markers developed from other Prunus species and with 40 SNPs obtained from 3′ UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity, and polymorphic information content values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, “Stella” was separated from “Compact Stella.” This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3′ UTR SNPs for genetic fingerprinting, parentage verification, gene mapping, and study of genetic diversity in sweet cherry. PMID:22737155

Purpose High mobility group box 1 (HMGB1) plays a central role in the pathogenesis of sepsis and multiple organ dysfunction syndromes. We investigated the associations of a single nucleotidepolymorphism (SNP; rs1045411) in HMGB1 with various clinical parameters, severity, and prognosis in patients with sepsis, severe sepsis, or septic shock. Materials and Methods We enrolled 212 adult patients followed for 28 days. All patients were genotyped for rs1045411, and the serum levels of HMGB1 and several cytokines were measured. Results The proportions of patients according to genotype were GG (71.2%), GA (26.4%), and AA (2.4%). Among patients with chronic lung disease comorbidity, patients with a variant A allele had higher positive blood culture rates and higher levels of various cytokines [interleukin (IL)-1β, IL-6, IL-10, IL-17, and tumor necrosis factor-α] than those with the GG genotype. In the analysis of those with diabetes as a comorbidity, patients with a variant A allele had higher blood culture and Gram-negative culture rates than those with GG genotypes; these patients also had a higher levels of IL-17. In the analysis of those with sepsis caused by a respiratory tract infection, patients with a variant A allele had higher levels of IL-10 and IL-17 (all p<0.05). This polymorphism had no significant impact on patient survival. Conclusion The variant A allele of rs1045411 appears to be associated with a more severe inflammatory response than the GG genotype under specific conditions. PMID:26632390

Background The aim of this study was to examine the associations between the single-nucleotidepolymorphisms (SNPs) of interleukin-17 (IL-17), including rs763780 (7488A/G), rs2275913 (–197G/A), and rs8193036 (–737C/T), and asthma susceptibility in an Asian population. Material/Methods From Oct 2013 to Dec 2014, 125 asthma patients enrolled in our hospital were selected as the case group. Another 132 healthy controls undergoing physical examinations in our hospital were enrolled as the control group. The genotype frequencies of IL-17 rs763780, rs2275913 and rs8193036 SNPs were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Comprehensive Meta-analysis 2.0 (CMA 2.0) software was applied for meta-analysis. Results Our results demonstrated that asthma patients presented with higher frequencies of GA genotype in rs2275913 and TT genotype in rs8193036 of IL-17 than healthy controls (both P<0.001). The genotype frequencies of IL-17 rs763780 between the asthma patients and healthy controls exhibited no significant differences (P>0.05). The comparisons on the rs2275913 and rs8193036 frequencies between the asthma patients and healthy controls were statistically significant in both allele and addictive models (all P<0.05). The frequency of IL-17 rs763780 between the asthma patients and healthy controls were statistically different in allele models (P<0.05), but not in addictive models (P>0.05). The overall results of our case-control study were further confirmed by meta-analysis. Conclusions Our results revealed that, in an Asian population, IL-17 rs763780, rs2275913, and rs8193036 SNPs may be associated with asthma susceptibility, and GA genotype in rs2275913 and TT genotype in rs8193036 of IL-17 may contribute to increased risk of asthma in Asians. PMID:26954344

Background: The human ADIPOQ gene encodes adiponectin protein hormone, which is involved in regulating glucose levels as well as fatty acid breakdown. It is exclusively produced by adipose tissue and abundantly present in the circulation, with concentration of around 0.01% of total serum proteins, with important effect on metabolism. Methods: Most deleterious nonsynonymous single nucleotidepolymorphisms in the coding region of the ADIPOQ gene were investigated using SNP databases, and detected nonsynonymous variants were analyzed in silico from the standpoint of relevant protein function and stability by using SIFT, PolyPhen-2, PROVEAN and MUpro, I-Mutant2.0 tools, respectively. Result: A total of 58 nonsynonymous SNPs consisting of 55 missense variations, 3 nonsense variations were found in the ADIPOQ gene. Next, 14 of the 55 missense variants were predicted to be damaging or deleterious by three different software programs (PolyPhen-2, SIFT, and PROVEAN), and 38 of them were predicted to be less stable (I-Mutant 2.0 and MUpro software). Totally, 10 variants out of 55 missense variants were predicted to be both deleterious and reduce protein stability. Additionally, 3 nonsense variants were predicted to produce a truncated ADIPOQ protein. RMSD and total energy were calculated for 4 nsSNPs out of 10 nsSNPs which were both deleterious and showed a decrease in protein stability. Conclusion: rs144526209 has high root-mean-square deviation (RMSD) and lower total energy value compared to the native modeled structure. It was concluded that this nsSNP, potentially functional and polymorphic in the ADIPOQ gene, might be associated with diabetes, obesity, and inflammation. PMID:26306152

BACKGROUND Children with 22q11.2 deletion syndrome (22q11.2DS) have a wide range of clinical features. TBX1 has been proposed as a candidate gene for some of the features in this condition. Polymorphisms in the non-deleted TBX1, which may affect the function of the sole TBX1 gene in individuals with the 22q11.2DS, may be a key to understanding the phenotypic variability among individuals with a shared deletion. Comprehensive single nucleotidepolymorphism (SNP) discovery by resequencing candidate genes can identify genetic variants that influence a given phenotype. The purpose of this study was to further characterize the sequence variability in TBX1 by identifying all common SNPs in this gene. METHODS We resequenced TBX1 in 29 children with a documented 22q11.2 deletion and 95 non-deleted, healthy individuals. We estimated allele frequencies, performed tagSNP selection, and inferred haplotypes. We also compared SNP frequencies between 22q11.2DS and control samples. RESULTS We identified 355 biallelic markers among the 190 chromosomes resequenced in the control panel. The vast majority of the markers identified were SNPs (n=331), and the remainder indels (n=24). We did not identify SNPs or indels in the cis- regulatory element (FOX–binding site) upstream of TBX1. In children with 22q11.2DS we detected 187 biallelic markers, six of which were indels. Four of the seven coding SNPs identified in the controls were identified in children with 22q11.2DS. CONCLUSIONS This comprehensive SNP discovery data can be used to select SNPs to genotype for future association studies assessing the role of TBX1 and phenotypic variability in individuals with 22q11.2DS. PMID:19645056

The next generation sequencing technologies produce unprecedented amounts of data on the genetic sequence of individual organisms. These sequences carry a substantial amount of variation that may or may be not related to a phenotype. Phenotypically important part of this variation often comes in form of protein-sequence altering (non-synonymous) single nucleotide variants (nsSNVs). Here we present StructMAn, a Web-based tool for annotation of human and non-human nsSNVs in the structural context. StructMAn analyzes the spatial location of the amino acid residue corresponding to nsSNVs in the three-dimensional (3D) protein structure relative to other proteins, nucleic acids and low molecular-weight ligands. We make use of all experimentally available 3D structures of query proteins, and also, unlike other tools in the field, of structures of proteins with detectable sequence identity to them. This allows us to provide a structural context for around 20% of all nsSNVs in a typical human sequencing sample, for up to 60% of nsSNVs in genes related to human diseases and for around 35% of nsSNVs in a typical bacterial sample. Each nsSNV can be visualized and inspected by the user in the corresponding 3D structure of a protein or protein complex. The StructMAn server is available at http://structman.mpi-inf.mpg.de. PMID:27150811

The next generation sequencing technologies produce unprecedented amounts of data on the genetic sequence of individual organisms. These sequences carry a substantial amount of variation that may or may be not related to a phenotype. Phenotypically important part of this variation often comes in form of protein-sequence altering (non-synonymous) single nucleotide variants (nsSNVs). Here we present StructMAn, a Web-based tool for annotation of human and non-human nsSNVs in the structural context. StructMAn analyzes the spatial location of the amino acid residue corresponding to nsSNVs in the three-dimensional (3D) protein structure relative to other proteins, nucleic acids and low molecular-weight ligands. We make use of all experimentally available 3D structures of query proteins, and also, unlike other tools in the field, of structures of proteins with detectable sequence identity to them. This allows us to provide a structural context for around 20% of all nsSNVs in a typical human sequencing sample, for up to 60% of nsSNVs in genes related to human diseases and for around 35% of nsSNVs in a typical bacterial sample. Each nsSNV can be visualized and inspected by the user in the corresponding 3D structure of a protein or protein complex. The StructMAn server is available at http://structman.mpi-inf.mpg.de. PMID:27150811

Brassica napus (oilseed rape, canola) is one of the world’s most important sources of vegetable oil for human nutrition and biofuel, and also a model species for studies investigating the evolutionary consequences of polyploidisation. Strong bottlenecks during its recent origin from interspecific hybridisation, and subsequently through intensive artificial selection, have severely depleted the genetic diversity available for breeding. On the other hand, high-throughput genome profiling technologies today provide unprecedented scope to identify, characterise and utilise genetic diversity in primary and secondary crop gene pools. Such methods also enable implementation of genomic selection strategies to accelerate breeding progress. The key prerequisite is availability of high-quality sequence data and identification of high-quality, genome-wide sequence polymorphisms representing relevant gene pools. We present comprehensive genome resequencing data from a panel of 52 highly diverse natural and synthetic B. napus accessions, along with a stringently selected panel of 4.3 million high-confidence, genome-wide SNPs. The data is of great interest for genomics-assisted breeding and for evolutionary studies on the origins and consequences in allopolyploidisation in plants. PMID:26647166

Brassica napus (oilseed rape, canola) is one of the world's most important sources of vegetable oil for human nutrition and biofuel, and also a model species for studies investigating the evolutionary consequences of polyploidisation. Strong bottlenecks during its recent origin from interspecific hybridisation, and subsequently through intensive artificial selection, have severely depleted the genetic diversity available for breeding. On the other hand, high-throughput genome profiling technologies today provide unprecedented scope to identify, characterise and utilise genetic diversity in primary and secondary crop gene pools. Such methods also enable implementation of genomic selection strategies to accelerate breeding progress. The key prerequisite is availability of high-quality sequence data and identification of high-quality, genome-wide sequence polymorphisms representing relevant gene pools. We present comprehensive genome resequencing data from a panel of 52 highly diverse natural and synthetic B. napus accessions, along with a stringently selected panel of 4.3 million high-confidence, genome-wide SNPs. The data is of great interest for genomics-assisted breeding and for evolutionary studies on the origins and consequences in allopolyploidisation in plants. PMID:26647166

The goal of this study was to compare significant SNP selection approaches in the context of complex traits based on SNP estimates obtained by models: a model fitting a single SNP (M1), a model fitting a single SNP and a random polygenic effect (M2), the nonparametric CAR score (M3), a SNP-BLUP model with random effects of all SNPs fitted simultaneously (M4). There were 46,267 SNPs tested in a population of 2601 Holstein Friesian bulls, four traits (milk and fat yields, somatic cell score, non-return rate for heifers) were considered. The numbers of SNPs selected as significant differed among models. M1 selected a very large number of SNPs, except for a NRH in which no SNPs were significant. M2 and M3 both selected similar and low number of SNPs for each trait. M4 selected more SNPs than M2 and M3. Considering linkage disequilibrium between SNPs, for MY M2 and M3 selected SNPs more highly correlated with each other than in the case of M4, while for FY M3 selection contained more correlated SNPs than M2 and M4. In conclusion, if the research interest is to identify SNPs not only with strong, but also with moderate effects on a complex trait a multiple-SNP model is recommended. Such models are capable of accounting for at least a part of linkage disequilibrium between SNPs through the design matrix of SNP effects. Functional annotation of SNPs significant in M4 reveals good correspondence between selected polymorphisms and functional information as well as with QTL mapping results. PMID:26294278

Colorectal cancer (CRC) is a highly heterogeneous disease regarding the stage at time of diagnosis and there is special attention regarding adjuvant chemotherapy in unselected patients with stage I and stage II. The clinicohistologically based TNM staging system with emphasis on histological evaluation of primary tumor and resected regional lymph nodes remains the standard of staging, but it has restricted sensitivity resulting in false downward stage migration. Molecular characteristics might predispose tumors to a worse prognosis and identification of those enables identifying patients with high risk of disease recurrence. Suitable predictive markers also enable choosing the most appropriate therapy. The current challenge facing adjuvant chemotherapy in stages I and II CRC is choosing patients with the highest risk of disease recurrence who are going to derive most benefit without facing unnecessary adverse effects. Single nucleotidepolymorphisms (SNPs) are one of the potential molecular markers that might help us identify patients with unfavorable prognostic factors regarding disease initiation and recurrence and could determine selection of an appropriate chemotherapy regimen in the adjuvant and metastatic setting. In this paper, we discuss SNPs of genes involved in the multistep processes of cancerogenesis, metastasis, and the metabolism of chemotherapy that might prove clinically significant. PMID:26884752

Varicella-zoster virus (VZV) is a causative agent for chickenpox and zoster. Live attenuated vaccines have been developed based on Oka and MAV/06 strains. In order to understand the molecular mechanisms of attenuation, complete genome sequences of vaccine and wild-type strains were compared and single nucleotidepolymorphism (SNP) was analyzed. ORF22 and ORF62 contained the highest number of SNPs. The detailed analysis of the SNPs suggested 24 potential vaccine-specific sites. All the mutational events found in vaccine-specific sites were transitional, and most of them were substitution of AT to GC pair. Interestingly, 18 of the vaccine-specific sites of the vaccine strains appeared to be genetically heterogeneous. The probability of a single genome of vaccine strain to contain all 24 vaccine-type sequences was calculated to be less than 4%. The average codon adaptation index (CAI) value of the vaccine strains was significantly lower than the CAI value of the clinical strains. PMID:27376245

Cytogenetic aberrations identified by metaphase cytogenetics (MC) have diagnostic, prognostic, and therapeutic implications in myelodysplastic syndromes (MDS). However, in some MDS patients MC study is unsuccesful. Single nucleotidepolymorphism array (SNP-A) based karyotyping could be helpful in these cases. We performed SNP-A in 62 samples from bone marrow or peripheral blood of primary MDS with an unsuccessful MC study. SNP-A analysis enabled the detection of aberrations in 31 (50%) patients. We used the copy number alteration information to apply the International Prognostic Scoring System (IPSS) and we observed differences in survival between the low/intermediate-1 and intermediate-2/high risk patients. We also saw differences in survival between very low/low/intermediate and the high/very high patients when we applied the revised IPSS (IPSS-R). In conclusion, SNP-A can be used successfully in PB samples and the identification of CNA by SNP-A improve the diagnostic and prognostic evaluation of this group of MDS patients. PMID:24123380

We present new methodology for calculating sampling distributions of single-nucleotidepolymorphism (SNP) frequencies in populations with time-varying size. Our approach is based on deriving analytical expressions for frequencies of SNPs. Analytical expressions allow for computations that are faster and more accurate than Monte Carlo simulations. In contrast to other articles showing analytical formulas for frequencies of SNPs, we derive expressions that contain coefficients that do not explode when the genealogy size increases. We also provide analytical formulas to describe the way in which the ascertainment procedure modifies SNP distributions. Using our methods, we study the power to test the hypothesis of exponential population expansion vs. the hypothesis of evolution with constant population size. We also analyze some of the available SNP data and we compare our results of demographic parameters estimation to those obtained in previous studies in population genetics. The analyzed data seem consistent with the hypothesis of past population growth of modern humans. The analysis of the data also shows a very strong sensitivity of estimated demographic parameters to changes of the model of the ascertainment procedure. PMID:14504247

Orbital meningiomas can be classified as primary optic nerve sheath (ON) meningiomas, primary intraorbital ectopic (Ob) meningiomas and spheno-orbital (Sph-Ob) meningiomas based on anatomic site. Single-nucleotidepolymorphism (SNP)-based array analysis with the Illumina 300K platform was performed on formalin-fixed, paraffin-embedded tissue from 19 orbital meningiomas (5 ON, 4 Ob and 10 Sph-Ob meningiomas). Tumors were World Health Organization (WHO) grade I except for two grade II meningiomas, and one was NF2-associated. We found genomic alterations in 68% (13 of 19) of orbital meningiomas. Sph-Ob tumors frequently exhibited monosomy 22/22q loss (70%; 7/10) and deletion of chromosome 1p, 6q and 19p (50% each; 5/10). Among genetic alterations, loss of chromosome 1p and 6q were more frequent in clinically progressive tumors. Chromosome 22q loss also was detected in the majority of Ob meningiomas (75%; 3/4) but was infrequent in ON meningiomas (20%; 1/5). In general, Ob tumors had fewer chromosome alterations than Sph-Ob and ON tumors. Unlike Sph-Ob meningiomas, most of the Ob and ON meningiomas did not progress even after incomplete excision, although follow-up was limited in some cases. Our study suggests that ON, Ob and Sph-Ob meningiomas are three molecularly distinct entities. Our results also suggest that molecular subclassification may have prognostic implications. PMID:24773246

The definition of haplotype blocks of single-nucleotidepolymorphisms (SNPs) has been proposed so that the haplotypes can be used as markers in association studies and to efficiently describe human genetic variation. The International Haplotype Map (HapMap) project to construct a comprehensive catalog of haplotypic variation in humans is underway. However, a number of factors have already been shown to influence the definition of blocks, including the population studied and the sample SNP density. Here, we examine the effect that marker selection has on the definition of blocks and the pattern of haplotypes by using comparable but complementary SNP sets and a number of block definition methods in various genomic regions and populations that were provided by the Encyclopedia of DNA Elements (ENCODE) project. We find that the chosen SNP set has a profound effect on the block-covered sequence and block borders, even at high marker densities. Our results question the very concept of discrete haplotype blocks and the possibility of generalizing block findings from the HapMap project. We comparatively apply the block-free tagging-SNP approach and discuss both the haplotype approach and the tagging-SNP approach as means to efficiently catalog genetic variation. PMID:16380910

Previously identified single nucleotidepolymorphisms (SNPs) in genome wide association studies (GWAS) of cardiovascular disease (CVD) in participants of mostly European descent were tested for association with subclinical cardiovascular disease (sCVD), coronary artery calcium score (CAC) and carotid intima media thickness (CIMT) in the Multi-Ethnic Study of Atherosclerosis (MESA). The data in this data in brief article correspond to the article Common Genetic Variants and Subclinical Atherosclerosis: The Multi-Ethnic Study of Atherosclerosis [1]. This article includes the demographic information of the participants analyzed in the article as well as graphical displays and data tables of the association of the selected SNPs with CAC and of the meta-analysis across ethnicities of the association of CIMT-c (common carotid), CIMT-I (internal carotid), CAC-d (CAC as dichotomous variable with CAC>0) and CAC-c (CAC as continuous variable, the log of the raw CAC score plus one) and CVD. The data tables corresponding to the 9p21 fine mapping experiment as well as the power calculations referenced in the article are also included. PMID:26958643

Systemic lupus erythematosus (SLE) is one of the common autoimmune diseases, with complex genetic components. Here, we report on a case-control association study of 178 SLE patients and 899 control subjects, using genome-wide gene-based single nucleotidepolymorphism (SNP) markers. An SNP, rs3130342, in a 5' flanking region of the TNXB gene revealed a significant association with SLE [P = 0.000000930, odds ratio (OR) 3.11, with 95% confidence interval (95%CI) of 1.89-5.28] in a Japanese population. This association was replicated independently with 203 cases and 294 controls (P = 0.0440, OR 1.52, with 95%CI of 1.01-2.78). Although a copy number variation (CNV) of the C4 gene adjacent to the TNXB gene was reported to be associated with SLE, our analysis on this CNV revealed that the association of CNV of the C4 gene was weaker than the SNP in the TNXB gene and likely to reflect the linkage disequilibrium between C4 CNV and this particular SNP. Stratified analysis also revealed that the association of SNP rs3130342 with SLE was independent of the HLA-DRB1*1501 allele that has been shown to be associated with SLE. Our findings strongly imply that the TNXB gene is a candidate gene susceptible to SLE in the Japanese population. PMID:18058064

Aldehyde dehydrogenase (ALDH) 2 is a mitochondrial enzyme that is known for its important role in oxidation and detoxification of ethanol metabolite acetaldehyde. ALDH2 also metabolizes other reactive aldehydes such as 4-hydroxy-2-nonenal and acrolein. The Glu504Lys single nucleotidepolymorphism (SNP) of ALDH2 gene, which is found in approximately 40% of the East Asian populations, causes defect in the enzyme activity of ALDH2, leading to alterations in acetaldehyde metabolism and alcohol-induced “flushing” syndrome. Evidence suggests that ALDH2 Glu504Lys SNP is a potential candidate genetic risk factor for a variety of chronic diseases such as cardiovascular disease, cancer, and late-onset Alzheimer's disease. In addition, the association between ALDH2 Glu504Lys SNP and the development of these chronic diseases appears to be affected by the interaction between the SNP and lifestyle factors such as alcohol consumption as well as by the presence of other genetic variations. PMID:26491656

Following human immunodeficiency virus type 1 (HIV-1) integration into host cell DNA, the viral promoter can become transcriptionally silent in the absence of appropriate signals and factors. HIV-1 gene expression is dependent on regulatory elements contained within the long terminal repeat (LTR) that drive the synthesis of viral RNAs and proteins through interaction with multiple host and viral factors. Previous studies identified single nucleotidepolymorphisms (SNPs) within CCAAT/enhancer binding protein (C/EBP) site I and Sp site III (3T, C-to-T change at position 3, and 5T, C-to-T change at position 5 of the binding site, respectively, when compared to the consensus B sequence) that are low affinity binding sites and correlate with more advanced stages of HIV-1 disease. Stably transfected cell lines containing the wild type, 3T, 5T, and 3T5T LTRs were developed utilizing bone marrow progenitor, T, and monocytic cell lines to explore the LTR phenotypes associated with these genotypic changes from an integrated chromatin-based microenvironment. Results suggest that in nonexpressing cell clones LTR-driven gene expression occurs in a SNP-specific manner in response to LTR activation or treatment with trichostatin A treatment, indicating a possible cell type and SNP-specific mechanism behind the epigenetic control of LTR activation. PMID:25629043

P53 is a key regulator of many cellular processes and is negatively regulated by the human homolog of murine double minute-2 (MDM2) E3 ubiquitin ligase. Single nucleotidepolymorphisms (SNPs) of either gene alone, and in combination, are linked to cancer susceptibility, disease progression, and therapy response. We analyzed the interaction of TP53 R72P and MDM2 SNP309 SNPs in relationship to outcome in patients with myelodysplastic syndromes (MDS). Sanger sequencing was performed on DNA isolated from 208 MDS cases. Utilizing a novel functional SNP scoring system ranging from +2 to -2 based on predicted p53 activity, we found statistically significant differences in overall survival (OS) (p = 0.02) and progression-free survival (PFS) (p = 0.02) in non-del(5q) MDS patients with low functional scores. In univariate analysis, only IPSS and the functional SNP score predicted OS and PFS in non-del(5q) patients. In multivariate analysis, the functional SNP score was independent of IPSS for OS and PFS. These data underscore the importance of TP53 R72P and MDM2 SNP309 SNPs in MDS, and provide a novel scoring system independent of IPSS that is predictive for disease outcome. PMID:26416416

The dengue and yellow fever mosquito, Aedes aegypti, contributes significantly to global disease burden. Genetic study of Aedes aegypti is essential to understanding its evolutionary history, competence as a disease vector, and the effects and efficacy of vector control methods. The prevalence of repeats and transposable elements in the Aedes aegypti genome complicates marker development and makes genome-wide genetic study challenging. To overcome these challenges, we developed a high-throughput genotyping chip, Axiom_aegypti1. This chip screens for 50,000 single-nucleotidepolymorphisms present in Aedes aegypti populations from around the world. The array currently used genotypes 96 samples simultaneously. To ensure that these markers satisfy assumptions commonly made in many genetic analyses, we tested for Mendelian inheritance and linkage disequilibrium in laboratory crosses and a wild population, respectively. We have validated more than 25,000 of these markers to date, and expect this number to increase with more sampling. We also present evidence of the chip's efficacy in distinguishing populations throughout the world. The markers on this chip are ideal for applications ranging from population genetics to genome-wide association studies. This tool makes rapid, cost-effective, and comparable genotype data attainable to diverse sets of Aedes aegypti researchers, from those interested in potential range shifts due to climate change to those characterizing the genetic underpinnings of its competence to transmit disease. PMID:25721127

Vitamin E (α-tocopherol) is the major lipid soluble antioxidant in most animal species. By controlling the secretion of vitamin E from the liver, the α-tocopherol transfer protein (αTTP) regulates whole-body distribution and levels of this vital nutrient. However, the mechanism(s) that regulate the expression of this protein are poorly understood. Here we report that transcription of the TTPA gene in immortalized human hepatocytes (IHH) is induced by oxidative stress and by hypoxia, by agonists of the nuclear receptors PPARα and RXR, and by increased cAMP levels. The data show further that induction of TTPA transcription by oxidative stress is mediated by an already-present transcription factor, and does not require de novo protein synthesis. Silencing of the cAMP response element binding (CREB) transcription factor attenuated transcriptional responses of the TTPA gene to added peroxide, suggesting that CREB mediates responses of this gene to oxidative stress. Using a 1.9 Kb proximal segment of the human TTPA promoter together with site-directed mutagenesis approach, we found that single nucleotidepolymorphisms (SNPs) that are commonly found in healthy humans dramatically affect promoter activity. These observations suggest that oxidative stress and individual genetic makeup contribute to vitamin E homeostasis in humans. These findings may explain the variable responses to vitamin E supplementation observed in human clinical trials. PMID:23079030

The Rex rabbit is a typical fur breed. Wool density, hair length, wool fineness, and hide area are the main indices of fur quality. We previously found that the CCNA2 gene plays an important role in hair follicle initiation and development, and it is involved in the distinctive wool density of the Rex rabbit. It is an important candidate gene for wool density selection through marker-assisted selection. We conducted an association study to identify single nucleotidepolymorphisms (SNPs) within the CCNA2 gene and their ligands associated with wool density. Using PCR-RFLP technology, we discovered two SNPs (129G>A and 1140G>C) of the CCNA2 gene. Allele frequencies of these two SNPs were investigated and evaluated by the χ(2) test in 100 Rex rabbits. The two SNPs were both in Hardy-Weinberg equilibrium. We also looked for a potential association of these SNPs with fur traits in 100 Rex rabbits. Rex rabbits with the GG genotype had significantly higher wool density (P < 0.01) than those with other genotypes; the other three fur traits did not differ significantly among the genotypes. In conclusion, the two SNPs of the CCNA2 gene affect wool density in the Rex rabbit. PMID:22095474

Previously identified single nucleotidepolymorphisms (SNPs) in genome wide association studies (GWAS) of cardiovascular disease (CVD) in participants of mostly European descent were tested for association with subclinical cardiovascular disease (sCVD), coronary artery calcium score (CAC) and carotid intima media thickness (CIMT) in the Multi-Ethnic Study of Atherosclerosis (MESA). The data in this data in brief article correspond to the article Common Genetic Variants and Subclinical Atherosclerosis: The Multi-Ethnic Study of Atherosclerosis [1]. This article includes the demographic information of the participants analyzed in the article as well as graphical displays and data tables of the association of the selected SNPs with CAC and of the meta-analysis across ethnicities of the association of CIMT-c (common carotid), CIMT-I (internal carotid), CAC-d (CAC as dichotomous variable with CAC>0) and CAC-c (CAC as continuous variable, the log of the raw CAC score plus one) and CVD. The data tables corresponding to the 9p21 fine mapping experiment as well as the power calculations referenced in the article are also included. PMID:26958643

The dengue and yellow fever mosquito, Aedes aegypti, contributes significantly to global disease burden. Genetic study of Aedes aegypti is essential to understanding its evolutionary history, competence as a disease vector, and the effects and efficacy of vector control methods. The prevalence of repeats and transposable elements in the Aedes aegypti genome complicates marker development and makes genome-wide genetic study challenging. To overcome these challenges, we developed a high-throughput genotyping chip, Axiom_aegypti1. This chip screens for 50,000 single-nucleotidepolymorphisms present in Aedes aegypti populations from around the world. The array currently used genotypes 96 samples simultaneously. To ensure that these markers satisfy assumptions commonly made in many genetic analyses, we tested for Mendelian inheritance and linkage disequilibrium in laboratory crosses and a wild population, respectively. We have validated more than 25,000 of these markers to date, and expect this number to increase with more sampling. We also present evidence of the chip’s efficacy in distinguishing populations throughout the world. The markers on this chip are ideal for applications ranging from population genetics to genome-wide association studies. This tool makes rapid, cost-effective, and comparable genotype data attainable to diverse sets of Aedes aegypti researchers, from those interested in potential range shifts due to climate change to those characterizing the genetic underpinnings of its competence to transmit disease. PMID:25721127

Vitamin E (α-tocopherol) is the major lipid-soluble antioxidant in most animal species. By controlling the secretion of vitamin E from the liver, the α-tocopherol transfer protein regulates whole-body distribution and levels of this vital nutrient. However, the mechanism(s) that regulates the expression of this protein is poorly understood. Here we report that transcription of the TTPA gene in immortalized human hepatocytes is induced by oxidative stress and by hypoxia, by agonists of the nuclear receptors PPARα and RXR, and by increased cAMP levels. The data show further that induction of TTPA transcription by oxidative stress is mediated by an already-present transcription factor and does not require de novo protein synthesis. Silencing of the cAMP response element-binding (CREB) transcription factor attenuated transcriptional responses of the TTPA gene to added peroxide, suggesting that CREB mediates responses of this gene to oxidative stress. Using a 1.9-kb proximal segment of the human TTPA promoter together with a site-directed mutagenesis approach, we found that single-nucleotidepolymorphisms that are commonly found in healthy humans dramatically affect promoter activity. These observations suggest that oxidative stress and individual genetic makeup contribute to vitamin E homeostasis in humans. These findings may explain the variable responses to vitamin E supplementation observed in human clinical trials. PMID:23079030

In genetic association studies, such as genome-wide association studies (GWAS), the number of single nucleotidepolymorphisms (SNPs) can be as large as hundreds of thousands. Due to linkage disequilibrium, many SNPs are highly correlated; assuming they are independent is not valid. The commonly used multiple comparison methods, such as Bonferroni correction, are not appropriate and are too conservative when applied to GWAS. To overcome these limitations, many approaches have been proposed to estimate the so-called effective number of independent tests to account for the correlations among SNPs. However, many current effective number estimation methods are based on eigenvalues of the correlation matrix. When the dimension of the matrix is large, the numeric results may be unreliable or even unobtainable. To circumvent this obstacle and provide better estimates, we propose a new effective number estimation approach which is not based on the eigenvalues. We compare the new method with others through simulated and real data. The comparison results show that the proposed method has very good performance. PMID:21849789

Recent analyses of human genome sequences have given rise to impressive advances in identifying non-synonymous single nucleotidepolymorphisms (nsSNPs). By contrast, the annotation of nsSNPs and their links to diseases are progressing at a much slower pace. Many of the current approaches to analysing disease-associated nsSNPs use primarily sequence and evolutionary information, while structural information is relatively less exploited. In order to explore the potential of such information, we developed a structure-based approach, Bongo (Bonds ON Graph), to predict structural effects of nsSNPs. Bongo considers protein structures as residue–residue interaction networks and applies graph theoretical measures to identify the residues that are critical for maintaining structural stability by assessing the consequences on the interaction network of single point mutations. Our results show that Bongo is able to identify mutations that cause both local and global structural effects, with a remarkably low false positive rate. Application of the Bongo method to the prediction of 506 disease-associated nsSNPs resulted in a performance (positive predictive value, PPV, 78.5%) similar to that of PolyPhen (PPV, 77.2%) and PANTHER (PPV, 72.2%). As the Bongo method is solely structure-based, our results indicate that the structural changes resulting from nsSNPs are closely associated to their pathological consequences. PMID:18654622

Although several genetic causes of male infertility are known, the condition in around 60.0-75.0% of infertile male patients appears to be idiopathic. In some, genetic causes may be polygenic and require several low-penetrance genes to produce a phenotype outcome. In others, pleiotropy, when a gene can produce several phenotypic traits, may be involved. We have investigated whether single nucleotidepolymorphisms (SNPs) in the SLC6A14 [solute carrier family 6 (amino acid transporter), member 14] gene are associated with male infertility. This gene has previously been linked with obesity and cystic fibrosis, which are associated with male infertility. It has a role in the transport of tryptophan and synthesis of serotonin that are important for normal spermatogenesis and testicular function. We have analyzed three SNPs (rs2312054, rs2071877 and rs2011162) in 370 infertile men and 241 fertile controls from two different populations (Macedonian and Slovenian). We found that the rs2011162(G) allele and rs2312054(A)-rs2071877(C)-rs2011162(G) haplotype are present at lower frequencies in the infertile rather than the fertile men (p = 0.044 and p = 0.0144, respectively). We concluded that the SLC6A14 gene may be a population-specific, low-penetrance locus which confers susceptibility to male infertility/subfertility. Additional follow-up studies of a large number of infertile men of different ethnic backgrounds are needed to confirm such a susceptibility. PMID:25937799

Although several genetic causes of male infertility are known, the condition in around 60.0–75.0% of infertile male patients appears to be idiopathic. In some, genetic causes may be polygenic and require several low-penetrance genes to produce a phenotype outcome. In others, pleiotropy, when a gene can produce several phenotypic traits, may be involved. We have investigated whether single nucleotidepolymorphisms (SNPs) in the SLC6A14 [solute carrier family 6 (amino acid transporter), member 14] gene are associated with male infertility. This gene has previously been linked with obesity and cystic fibrosis, which are associated with male infertility. It has a role in the transport of tryptophan and synthesis of serotonin that are important for normal spermatogenesis and testicular function. We have analyzed three SNPs (rs2312054, rs2071877 and rs2011162) in 370 infertile men and 241 fertile controls from two different populations (Macedonian and Slovenian). We found that the rs2011162(G) allele and rs2312054(A)-rs2071877(C)-rs2011162(G) haplotype are present at lower frequencies in the infertile rather than the fertile men (p = 0.044 and p = 0.0144, respectively). We concluded that the SLC6A14 gene may be a population-specific, low-penetrance locus which confers susceptibility to male infertility/subfertility. Additional follow-up studies of a large number of infertile men of different ethnic backgrounds are needed to confirm such a susceptibility. PMID:25937799

Background In recent years, several genomic regions have been robustly associated with coronary artery disease (CAD) in different genome-wide association studies (GWASs) conducted mainly in people of European descent. These kinds of data are lacking in African populations, even though heart diseases are a major cause of premature death and disability. Methods Here, 384 single nucleotidepolymorphisms (SNPs) in the top four CAD risk regions (1p13, 1q41, 9p21, and 10q11) were genotyped in 274 case-control samples from Morocco and Tunisia, with the aim of analyzing for the first time if the associations found in European populations were transferable to North Africans. Results The results indicate that, as in Europe, these four genetic regions are also important for CAD risk in North Africa. However, the individual SNPs associated with CAD in Africa are different from those identified in Europe in most cases (1p13, 1q41, and 9p21). Moreover, the seven risk variants identified in North Africans are efficient in discriminating between cases and controls in North African populations, but not in European populations. Conclusions This study indicates a disparity in markers associated to CAD susceptibility between North Africans and Europeans that may be related to population differences in the chromosomal architecture of these risk regions. PMID:26780859

Bromodomain testis-specific (BRDT) protein is essential for the normal process of spermatogenesis. Mutant mice that expressed truncated BRDT had impaired testicular histology with severely reduced sperm concentration and abnormal sperm morphology, while a model of knockout Brdt mice with no BRDT protein had complete meiotic arrest. A BRDT single nucleotidepolymorphism (SNP) (rs3088232) was reported as being associated with infertility in men. We assessed testicular specimens of 276 azoospermic men who underwent testicular sperm extraction to search for specimens that showed spermatogenic impairments similar to those of mutant BRDT mice. Ten similar specimens were selected for BRDT gene sequencing and they revealed three NCBI-reported SNPs (rs10783071, rs3088232 and rs10747493) variously distributed among them. Bioinformatics analysis predicted that they would not affect protein activity. Further assessment of rs3088232 frequency in a large group of non-obstructive azoospermia men and fertile controls demonstrated no significant difference between them (27.2 and 21.7% respectively; p = 0.122, Fisher's exact test). We conclude that the testicular impairments observed in the 10 specimens were not a consequence of BRDT gene mutation. The association between BRDT rs3088232 and infertility that had been reported in other studies was not supported. PMID:24865796

Identifying regulatory elements and revealing their role in gene expression regulation remains a central goal of plant genome research. We exploited the detailed genomic sequencing information of a large number of Arabidopsis (Arabidopsis thaliana) accessions to characterize known and to identify novel cis-regulatory elements in gene promoter regions of Arabidopsis by relying on conservation as the hallmark signal of functional relevance. Based on the genomic layout and the obtained density profiles of single-nucleotidepolymorphisms (SNPs) in sequence regions upstream of transcription start sites, the average length of promoter regions in Arabidopsis could be established at 500 bp. Genes associated with high degrees of variability of their respective upstream regions are preferentially involved in environmental response and signaling processes, while low levels of promoter SNP density are common among housekeeping genes. Known cis-elements were found to exhibit a decreased SNP density than sequence regions not associated with known motifs. For 15 known cis-element motifs, strong positional preferences relative to the transcription start site were detected based on their promoter SNP density profiles. Five novel candidate cis-element motifs were identified as consensus motifs of 17 sequence hexamers exhibiting increased sequence conservation combined with evidence of positional preferences, annotation information, and functional relevance for inducing correlated gene expression. Our study demonstrates that the currently available resolution of SNP data offers novel ways for the identification of functional genomic elements and the characterization of gene promoter sequences. PMID:24204023

Copy number variation (CNV), an essential form of genetic variation, has been increasingly recognized as one promising genetic marker in the analysis of animal genomes. Here, we used the Equine 70K single nucleotidepolymorphism genotyping array for the genome-wide detection of CNVs in 96 horses from three diverse Chinese breeds: Debao pony (DB), Mongolian horse (MG) and Yili horse (YL). A total of 287 CNVs were determined and merged into 122 CNV regions (CNVRs) ranging from 199 bp to 2344 kb in size and distributed in a heterogeneous manner on chromosomes. These CNVRs were integrated with seven existing reports to generate a composite genome-wide dataset of 1558 equine CNVRs, revealing 69 (56.6%) novel CNVRs. The majority (69.7%) of the 122 CNVRs overlapped with 438 genes, whereas 30.3% were located in intergenic regions. Most of these genes were associated with common CNVRs, which were shared by divergent horse breeds. As many as 60, 42 and 91 genes overlapping with the breed-specific ss were identified in DB, MG and YL respectively. Among these genes, FGF11, SPEM1, PPARG, CIDEB, HIVEP1 and GALR may have potential relevance to breed-specific traits. These findings provide valuable information for understanding the equine genome and facilitating association studies of economically important traits with equine CNVRs in the future. PMID:27440410

High-density single nucleotidepolymorphism (SNP) genotyping arrays are a powerful tool for studying genomic patterns of diversity, inferring ancestral relationships between individuals in populations and studying marker–trait associations in mapping experiments. We developed a genotyping array including about 90 000 gene-associated SNPs and used it to characterize genetic variation in allohexaploid and allotetraploid wheat populations. The array includes a significant fraction of common genome-wide distributed SNPs that are represented in populations of diverse geographical origin. We used density-based spatial clustering algorithms to enable high-throughput genotype calling in complex data sets obtained for polyploid wheat. We show that these model-free clustering algorithms provide accurate genotype calling in the presence of multiple clusters including clusters with low signal intensity resulting from significant sequence divergence at the target SNP site or gene deletions. Assays that detect low-intensity clusters can provide insight into the distribution of presence–absence variation (PAV) in wheat populations. A total of 46 977 SNPs from the wheat 90K array were genetically mapped using a combination of eight mapping populations. The developed array and cluster identification algorithms provide an opportunity to infer detailed haplotype structure in polyploid wheat and will serve as an invaluable resource for diversity studies and investigating the genetic basis of trait variation in wheat. PMID:24646323

A considerable number of single nucleotidepolymorphisms (SNPs) are required to elucidate genotype-phenotype associations and determine the molecular basis of important traits. In this work, we carried out de novo SNP discovery accounting for both genome duplication and genetic variation from American and European salmon populations. A total of 9 736 473 nonredundant SNPs were identified across a set of 20 fish by whole-genome sequencing. After applying six bioinformatic filtering steps, 200 K SNPs were selected to develop an Affymetrix Axiom(®) myDesign Custom Array. This array was used to genotype 480 fish representing wild and farmed salmon from Europe, North America and Chile. A total of 159 099 (79.6%) SNPs were validated as high quality based on clustering properties. A total of 151 509 validated SNPs showed a unique position in the genome. When comparing these SNPs against 238 572 markers currently available in two other Atlantic salmon arrays, only 4.6% of the SNP overlapped with the panel developed in this study. This novel high-density SNP panel will be very useful for the dissection of economically and ecologically relevant traits, enhancing breeding programmes through genomic selection as well as supporting genetic studies in both wild and farmed populations of Atlantic salmon using high-resolution genomewide information. PMID:26849107

Brahman cattle are important in tropical regions due to their ability to tolerate excessive heat and parasites. However, Brahman cattle exhibit lower carcass quality characteristics when compared to Bos taurus breeds. The objective of this study was to evaluate potential associations between single nucleotidepolymorphisms (SNPs) in six candidate genes for carcass quality and composition traits in a population of Brahman and Brahman-influenced steers. Steers were evaluated through the American Brahman Breeders Association carcass evaluation project in Gonzales, Texas. Carcass traits measured included hot carcass weight, ribeye area, marbling score, yield grade, quality grade, dressing percent, and Warner-Bratzler shear force score. Six previously described candidate genes were chosen for SNP analysis based on their previous association with growth and carcass traits. Candidate genes utilized in the current study included calpastatin (CAST), calpain (CAPN3), thyroglobulin (TG), growth hormone, insulin growth factor 1, and adiponectin. Six unique SNPs from three candidate genes (TG, CAST, and CAPN3) were significantly associated (P < 0.001) with carcass quality traits (marbling score and quality grade). A genotypic effect was observed for all significant SNPs, with differing levels of performance observed for animals inheriting different genotypes. Although multiple SNPs in the current study were significantly (P < 0.001) associated with growth and carcass traits, they should be validated in larger populations prior to implementation in selection strategies. PMID:27420951

The mapping of specific single nucleotidepolymorphisms (SNPs) in patients' genome is a critical process for the development of personalized therapy. In this work, a DNA microarray-based resonance light scattering (RLS) assay has been developed for multiplexed detection of breast cancer related SNPs with high sensitivity and selectivity. After hybridization of the desired target single-stranded DNAs (ssDNAs) with the ssDNA probes on a microarray, the polyvalent ssDNA modified 13 nm gold nanoparticles (GNPs) are employed to label the hybridization reaction through the formation of a three-stranded DNA system. The H2O2-mediated enlargement of GNPs is then used to enhance the RLS signal. The microarray-based RLS assay provides a detection limit of 10 pM (S/N = 3) for the target ssDNA and determines an allele frequency as low as 1.0% in the target ssDNA cocktail. Combined with an asymmetric PCR technique, the proposed assay shows good accuracy and sensitivity in profiling 4 SNPs related to breast cancer of three selected cell lines. PMID:26899365

The objective of this study was to evaluate whether renal cell carcinoma (RCC) risk-associated single nucleotidepolymorphisms (SNPs) could reflect the individual inherited risks of RCC. A total of 346 RCC patients and 1,130 controls were recruited in this case-control study. Genetic scores were calculated for each individual based on the odds ratios and frequencies of risk-associated SNPs. Four SNPs were significantly associated with RCC in Chinese population. Two genetic score models were established, genetic score 1 (rs10054504, rs7023329 and rs718314) and genetic score 2 (rs10054504, rs7023329 and rs1049380). For genetic score 1, the individual likelihood of RCC with low (<0.8), medium (0.8-1.2) and high (≥1.2) genetic score 1 was 15.61%, 22.25% and 33.92% respectively (P-trend=6.88×10−7). For genetic score 2, individual with low (<0.8), medium (0.8-1.2) and high (≥1.2) genetic score 2 would have likelihood of RCC as 14.39%, 24.54% and 36.48%, respectively (P-trend=1.27×10−10). The area under the receiver operating curve (AUC) of genetic score 1 was 0.626, and AUC of genetic score 2 was 0.658. We concluded that genetic score can reveal personal risk and inherited risk of RCC, especially when family history is not available. PMID:27229762

Chalkbrood is a disease affecting honey bees that seriously impairs brood growth and productivity of diseased colonies. Although honey bees can develop chalkbrood resistance naturally, the details underlying the mechanisms of resistance are not fully understood, and no easy method is currently available for selecting and breeding resistant bees. Finding the genes involved in the development of resistance and identifying single nucleotidepolymorphisms (SNPs) that can be used as molecular markers of resistance is therefore a high priority. We conducted genome resequencing to compare resistant (Res) and susceptible (Sus) larvae that were selected following in vitro chalkbrood inoculation. Twelve genomic libraries, including 14.4 Gb of sequence data, were analysed using SNP-finding algorithms. Unique SNPs derived from chromosomes 2 and 11 were analysed in this study. SNPs from resistant individuals were confirmed by PCR and Sanger sequencing using in vitro reared larvae and resistant colonies. We found strong support for an association between the C allele at SNP C2587245T and chalkbrood resistance. SNP C2587245T may be useful as a genetic marker for the selection of chalkbrood resistance and high royal jelly production honey bee lines, thereby helping to minimize the negative effects of chalkbrood on managed honey bees. PMID:26991518

Allergic rhinitis is a major public health problem and has seen its prevalence increase during the past few decades. Interleukin 13 (IL-13) has been implicated in the pathogenesis and in the regulation of immunoglobulin E (IgE) production. Single nucleotidepolymorphisms (SNPs) have been found in both the coding sequence and the promoter region of IL-13, and such SNPs have been associated with allergic asthma. We have investigated whether IL-13 SNPs are associated with allergic rhinitis. Among 188 Chinese adult patients with allergic rhinitis and 87 normal controls, no significant difference was found in either allele or haplotype frequency of the SNPs between the two groups. Within patients, there was a significant association of the IL-13 Arg130Gln SNP, but not of the IL-13 promoter -1112(C/T) SNP, with serum total IgE levels. Patients with a Gln/Gln genotype showed much higher serum total IgE than those with an Arg/Arg genotype. When tested for serum-specific IgE, patients allergic to Derp 1, but not those allergic to Artemisia pollen, showed a significant association with the IL-13 promoter SNP. Thus, our results suggest a possible involvement of IL-13 SNPs in the regulation of IgE production in response to allergens in this Chinese population. PMID:12928861

To diagnose brucellosis effectively, many genus- and species-specific detection methods based on PCR have been developed. With conventional PCR assays, real-time PCR techniques have been developed as rapid diagnostic tools. Among them, real-time PCR using hybridization probe (hybprobe) has been recommended for bacteria with high DNA homology among species, with which it is possible to make an accurate diagnosis by means of an amplification curve and melting peak analysis. A hybprobe for B. abortus was designed from a specific single-nucleotidepolymorphism (SNP) on the fbaA gene. This probe only showed specific amplification of B. abortus from approximately the 14th cycle, given a melting peak at 69°C. The sensitivity of real-time PCR was revealed to be 20 fg/µl by 10-fold DNA dilution, and the detection limit was 4 CFU in clinical samples. This real-time PCR showed greater sensitivity than that of conventional PCR and previous real-time PCR based on Taqman probe. Therefore, this new real-time PCR assay could be helpful for differentiating B. abortus infection with rapidity and accuracy. PMID:26666176

Summary Predictive biomarkers are needed in ITP. Single nucleotidepolymorphisms (SNPs) in beta 1 tubulin are potential candidates, as beta 1 tubulin is integral for platelet production and function, and SNPs in beta 1 tubulin have been associated with distinct phenotypes in platelets. We investigated the most prevalent beta 1 tubulin SNP (R307H) as a biomarker in patients with ITP via a retrospective chart review. Allelic frequencies between a group of 191 ITP patients and a healthy control group showed no difference, suggesting no direct etiologic role for the SNP in ITP. However, over similar periods of follow-up, both heterozygote and homozygote minor allele ITP patients were treated with significantly more treatment modalities and had significantly higher risk of failure to immune-modulatory therapies (RR=1.5, 95%CI=1.1–2.1;p=0.01); with rituximab, in particular, ITP patients with the SNP experienced a 58% failure rate (RR=1.6, 95%CI=1.03–2.5; p=0.04). Analysis of the absolute immature platelet fraction (A-IPF) as a marker of platelet production showed that SNP patients had significantly higher median A-IPFs compared to non-SNP patients when complete responses were achieved using immune modulatory therapies. The data suggest that the beta 1 tubulin R307H SNP has potential for use as a biomarker in ITP and may affect platelet turnover. PMID:23157319

Genome-wide association studies (GWAS) are a common approach for systematic discovery of single nucleotidepolymorphisms (SNPs) which are associated with a given disease. Univariate analysis approaches commonly employed may miss important SNP associations that only appear through multivariate analysis in complex diseases. However, multivariate SNP analysis is currently limited by its inherent computational complexity. In this work, we present a computational framework that harnesses supercomputers. Based on our results, we estimate a three-way interaction analysis on 1.1 million SNP GWAS data requiring over 5.8 years on the full "Avoca" IBM Blue Gene/Q installation at the Victorian Life Sciences Computation Initiative. This is hundreds of times faster than estimates for other CPU based methods and four times faster than runtimes estimated for GPU methods, indicating how the improvement in the level of hardware applied to interaction analysis may alter the types of analysis that can be performed. Furthermore, the same analysis would take under 3 months on the currently largest IBM Blue Gene/Q supercomputer "Sequoia" at the Lawrence Livermore National Laboratory assuming linear scaling is maintained as our results suggest. Given that the implementation used in this study can be further optimised, this runtime means it is becoming feasible to carry out exhaustive analysis of higher order interaction studies on large modern GWAS. PMID:25870758

To diagnose brucellosis effectively, many genus- and species-specific detection methods based on PCR have been developed. With conventional PCR assays, real-time PCR techniques have been developed as rapid diagnostic tools. Among them, real-time PCR using hybridization probe (hybprobe) has been recommended for bacteria with high DNA homology among species, with which it is possible to make an accurate diagnosis by means of an amplification curve and melting peak analysis. A hybprobe for B. abortus was designed from a specific single-nucleotidepolymorphism (SNP) on the fbaA gene. This probe only showed specific amplification of B. abortus from approximately the 14th cycle, given a melting peak at 69°C. The sensitivity of real-time PCR was revealed to be 20 fg/µl by 10-fold DNA dilution, and the detection limit was 4 CFU in clinical samples. This real-time PCR showed greater sensitivity than that of conventional PCR and previous real-time PCR based on Taqman probe. Therefore, this new real-time PCR assay could be helpful for differentiating B. abortus infection with rapidity and accuracy. PMID:26666176

The effect of resistin (RETN) on the response to anti-HCV therapy remains unclear. A prospective cohort study was performed using 655 consecutive HCV patients, of whom 513 had completed a course of interferon-based therapy. Multivariate and GEE analyses revealed four RETN single-nucleotidepolymorphisms (SNPs), rs34861192, rs3219175, rs3745367 and rs1423096, to be synergistically associated with resistin levels. After adjusting for co-factors such as interferon λ-3 (IFNL3)-rs12979860, the resistin level and the hyper-resistinemic genotype at the 4 RETN SNPs were positively and negatively associated with a sustained virological response (SVR), respectively. RETN-rs3745367 was in linkage disequilibrium with IFNL3-rs12979860. Compared to non-SVR patients, SVR patients had higher levels of pre-therapy resistin, primarily originating from intrahepatic lymphocytes, stellate cells, Kupffer cells, hepatic progenitor cells and hepatocytes. This difference diminished over the course of therapy, as only SVR patients exhibited a 24-week post-therapy decrease in resistin. Both resistin and IFNL3 mRNAs were upregulated, but only resistin mRNA was upregulated by recombinant resistin in peripheral blood mononuclear cells with and without hyper-resistinemic genotypes of the 4 RETN SNPs, respectively. Fine-tuned by RETN SNPs, intrahepatic, multi-cellular resistin reinforced IFNL3 in eliminating HCV via immunomodulation to counteract pro-inflammation. These results encourage the development of novel resistin-targeted anti-viral agents. PMID:27477870

Purpose Neuroblastoma is a childhood cancer of the sympathetic nervous system and many patients present with high risk disease. Risk stratification, based on pathology and tumor-derived biomarkers, has improved prediction of clinical outcomes, but overall survival rates remain unfavorable and new therapeutic targets are needed. Some studies suggest a link between interleukin-6 and more aggressive behavior in neuroblastoma tumor cells. Therefore, we examined the impact of two IL-6 single nucleotidepolymorphisms (SNP) on neuroblastoma disease progression. Experimental design DNA samples from 96 high risk neuroblastoma patients were screened for two SNP that are known to regulate the serum levels of IL-6 and the soluble IL-6 receptor (IL-6R), rs1800795 and rs8192284 respectively. The genotype for each SNP was determined in a blinded fashion and independent statistical analysis was performed to determine SNP-related event free survival (EFS) and overall survival (OS) rates. Results The rs1800795 IL-6 promoter SNP is an independent prognostic factor for EFS and OS in -high risk neuroblastoma patients. In contrast, the rs8192284 IL-6 receptor SNP revealed no prognostic value. Conclusions The rs1800795 SNP (-174 IL-6 (G>C) represents a novel and independent prognostic marker for both EFS and OS in high risk neuroblastoma. Since the rs1800795 SNP (-174 IL-6 (G>C) has been shown to correlate with production of IL-6, this cytokine may represent a target for development of new therapies in neuroblastoma. PMID:19671870

Phenotypic variation between human populations in skin pigmentation correlates with latitude at the continental level. A large number of hypotheses involving genetic adaptation have been proposed to explain human variation in skin colour, but only limited genetic evidence for positive selection has been presented. To shed light on the evolutionary genetic history of human variation in skin colour we inspected 118 genes associated with skin pigmentation in the Perlegen dataset, studying single nucleotidepolymorphisms (SNPs), and analyzed 55 genes in detail. We identified eight genes that are associated with the melanin pathway (SLC45A2, OCA2, TYRP1, DCT, KITLG, EGFR, DRD2 and PPARD) and presented significant differences in genetic variation between Europeans, Africans and Asians. In six of these genes we detected, by means of the EHH test, variability patterns that are compatible with the hypothesis of local positive selection in Europeans (OCA2, TYRP1 and KITLG) and in Asians (OCA2, DCT, KITLG, EGFR and DRD2), whereas signals were scarce in Africans (DCT, EGFR and DRD2). Furthermore, a statistically significant correlation between genotypic variation in four pigmentation candidate genes and phenotypic variation of skin colour in 51 worldwide human populations was revealed. Overall, our data also suggest that light skin colour is the derived state and is of independent origin in Europeans and Asians, whereas dark skin color seems of unique origin, reflecting the ancestral state in humans. PMID:17233754

Background Cattle are a reservoir of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157), and are known to harbor subtypes not typically found in clinically ill humans. Consequently, nucleotidepolymorphisms previously discovered via strains originating from human outbreaks may be restricted in their ability to distinguish STEC O157 genetic subtypes present in cattle. The objectives of this study were firstly to identify nucleotidepolymorphisms in a diverse sampling of human and bovine STEC O157 strains, secondly to classify strains of either bovine or human origin by polymorphism-derived genotypes, and finally to compare the genotype diversity with pulsed-field gel electrophoresis (PFGE), a method currently used for assessing STEC O157 diversity. Results High-throughput 454 sequencing of pooled STEC O157 strain DNAs from human clinical cases (n = 91) and cattle (n = 102) identified 16,218 putative polymorphisms. From those, 178 were selected primarily within genomic regions conserved across E. coli serotypes and genotyped in 261 STEC O157 strains. Forty-two unique genotypes were observed that are tagged by a minimal set of 32 polymorphisms. Phylogenetic trees of the genotypes are divided into clades that represent strains of cattle origin, or cattle and human origin. Although PFGE diversity surpassed genotype diversity overall, ten PFGE patterns each occurred with multiple strains having different genotypes. Conclusions Deep sequencing of pooled STEC O157 DNAs proved highly effective in polymorphism discovery. A polymorphism set has been identified that characterizes genetic diversity within STEC O157 strains of bovine origin, and a subset observed in human strains. The set may complement current techniques used to classify strains implicated in disease outbreaks. PMID:19463166

Hippocampal volume is a key brain structure for learning ability and memory process, and hippocampal atrophy is a recognized biological marker of Alzheimer's disease. However, the genetic bases of hippocampal volume are still unclear although it is a heritable trait. Genome-wide association studies (GWASs) on hippocampal volume have implicated several significantly associated genetic variants in Europeans. Here, to test the contributions of these GWASs identified genetic variants to hippocampal volume in different ethnic populations, we screened the GWAS-identified candidate single-nucleotidepolymorphisms in 3 independent healthy Asian brain imaging samples (a total of 990 subjects). The results showed that none of these single-nucleotidepolymorphisms were associated with hippocampal volume in either individual or combined Asian samples. The replication results suggested a complexity of genetic architecture for hippocampal volume and potential genetic heterogeneity between different ethnic populations. PMID:25131003

The gene encoding macrophage migration inhibitory factor (MIF) has been proposed as candidate tuberculosis (TB) susceptibility gene. In order to elucidate whether MIF gene variants are associated with susceptibility to retreatment cases of TB, and prevent drug-resistant TB prevalence, we conducted a study based on paired human population data. MIF -173 G/C single nucleotidepolymorphisms (rs755622) were genotyped using polymerase chain reaction-restriction fragment length polymorphism. MIF levels were detected with enzyme-linked immunosorbent assay. Association analysis of polymorphism to TB showed that distribution of MIF -173 genotypes (GC+CC) was significantly higher in total cases of TB than in the controls. Statistically significant differences of frequencies for MIF -173 (GG vs. GC+CC) were demonstrated when comparing total cases of TB, new cases of TB, and retreatment cases of TB to controls, respectively. In contrast, the frequencies of MIF -173 (GG vs. GC+CC) demonstrated no difference between new cases of TB and retreatment cases of TB. Association analysis of MIF protein concentrations to TB indicated that MIF concentration is significantly higher in total cases of TB, new cases of TB, and retreatment cases of TB than in controls (P<0.01). In summary, our results demonstrated that MIF gene -173 G/C single nucleotidepolymorphisms implicate in genetic susceptibility to TB, and GC+CC of MIF -173 site increases the risk of TB. We also found that no correlation between -173 G/C single nucleotidepolymorphism and retreatment cases of TB in Yunnan Province population of China. PMID:26656832

Background Activation and signal transduction in the Nucleotide binding, leucine-rich repeat containing receptor (NLR) family needs to be tightly regulated in order to control the inflammatory response to exogenous and endogenous danger signals. Phosphorylation is a common cellular mechanism of regulation that has recently been shown to be important in signalling in another family of cytoplasmic pattern recognition receptors, the RIG-I like receptors. In addition, single nucleotidepolymorphisms can alter receptor activity, potentially leading to dysfunction and/or a predisposition to inflammatory barrier diseases. Findings We have computationally analysed the N-terminus of NOD1 and found seven theoretical phosphorylation sites in, or immediately before, the NOD1 Caspase Activation Domain (CARD). Two of these, serine 7 and tyrosine 49 are also found as rare polymorphisms in the African-American population and European-American populations respectively. Mutating serine 7 to either an aspartic acid or an asparagine to mimic the potential impact of phosphorylation or the polymorphism respectively did not affect the response of NOD1 to ligand-mediated NFκB signalling. Conclusions The NOD1 polymorphism S7N does not interfere with receptor function in response to ligand stimulation. PMID:24598002

The most important traits of Chinese Liaoning cashmere goat fiber are fiber diameter, weight, and length. We looked for polymorphisms and their possible association with cashmere fiber traits in the 5' upstream region (5' UTR) of the prolactin receptor gene (PRLR), which encodes an anterior pituitary peptide hormone involved in different physiological activities; it is the principal endocrine regulator in pelage replacement in mammals. A novel single-nucleotidepolymorphism (SNP) was found in the 5' UTR of PRLR by PCR-RFLP in an analysis of 590 goats. Two genotypes (CC and CT) were observed. The frequencies of allele C and T were 0.93 and 0.07, respectively. Association analysis revealed that the PRLR 5' UTR polymorphism (SNP5) was significantly associated with cashmere fiber weight and diameter. This novel SNP in hircine PRLR has potential as a molecular marker for cashmere fiber weight and diameter in Liaoning cashmere goats. PMID:22009863

Mitochondrial DNA (mtDNA) variations including single nucleotidepolymorphisms (SNPs) have been proposed to be involved in idiosyncratic drug reactions. However, current in vitro and in vivo models lack the genetic diversity seen in the human population. Our hypothesis is that different cell strains with distinct mtDNA SNPs may have different mitochondrial bioenergetic profiles and may therefore vary in their response to drug-induced toxicity. Therefore, we used an in vitro system composed of four strains of mouse embryonic fibroblasts (MEFs) with mtDNA polymorphisms. We sequenced mtDNA from embryonic fibroblasts isolated from four mouse strains, C57BL/6J, MOLF/EiJ, CZECHII/EiJ and PERA/EiJ, with the latter two being sequenced for the first time. The bioenergetic profile of the four strains of MEFs was investigated at both passages 3 and 10. Our results showed that there were clear differences among the four strains of MEFs at both passages, with CZECHII/EiJ having a lower mitochondrial robustness when compared to C57BL/6J, followed by MOLF/EiJ and PERA/EiJ. Seven drugs known to impair mitochondrial function were tested for their effect on the ATP content of the four strains of MEFs in both glucose- and galactose-containing media. Our results showed that there were strain-dependent differences in the response to some of the drugs. We propose that this model is a useful starting point to study compounds that may cause mitochondrial off-target toxicity in early stages of drug development, thus decreasing the number of experimental animals used. -- Highlights: ► mtDNA SNPs may be linked to individual predisposition to drug-induced toxicity. ► CZECHII/EiJ and PERA/EiJ mtDNA was sequenced for the first time in this study. ► Strain-dependent mitochondrial capacity differences were measured. ► Strain-dependent differences in response to mitochondrial toxicants were observed.

Background The eye disorder associated with Graves’ disease, called Graves’ ophthalmopathy (GO), greatly reduces the quality of life in affected patients. Expression of the calsequestrin (CASQ1) protein in thyroid tissue may be the trigger for the development of eye muscle damage in patients with GO. We determined the prevalence of rs74123279, rs3747673, and rs2275703 single-nucleotidepolymorphism (SNPs) in patients with autoimmune thyroid disorders, GO, Graves’ hyperthyroidism (GH), or Hashimoto’s thyroiditis (HT) and control subjects with no personal or family history of autoimmune thyroid disorders. Furthermore, we measured the concentration of the CASQ1 protein in normal and Graves’ thyroid tissue, correlating levels with parameters of the eye signs, CASQ1 antibody levels, and the CASQ1 gene polymorphism rs74123279 and rs2275703. Methods High-quality genomic DNA was isolated from fresh blood samples, assayed for identification of rs74123279, rs3747673, and rs2275703 SNPs in CASQ1 gene by MassARRAY SNP analysis using iPLEX technology of SEQUENOM. Results DNA samples from 300 patients and 106 control subjects (100 males, 306 females) with GO (n=74), GH (n=130), HT (n=96) and control subjects (n=106) were genotyped for the SNPs rs74123279, rs3747673 (n=405), and rs2275703 (n=407). The SNP rs74123279, rs3747673, and rs2275703 were identified as 1) common homozygous or wild type, 2) heterozygote, and 3) rare homozygous. Minor allele frequency for rs74123279, rs3747763, and rs2275703 were 21%, 40%, and 44%, respectively. Multiple comparisons of genotype frequency for rs74123279, rs3747763, and rs2275703 in the GO, GH, HT, and control groups showed P=0.06, 0.641, and 0.189, respectively. These results were substantiated by multiple comparison of alleles frequency for rs74123279, rs3838216, rs3747763, and rs2275703 in the GO, GH, HT, and control groups showed, P=0.36, 0.008, 0.66, and 0.05, respectively. Pairwise analysis of alleles frequency distribution in

(1) Ghrelin is a novel endogenous ligand for the growth hormone secretagogue receptor (GHS-R) and is expressed primarily in the stomach and hypothalamus with the probable function of stimulating GH secretion and food intake both in mammals and poultry. The complete sequences of ghrelin gene have been reported in humans and mice; however, that of chickens remains unclear. (2) Here, we report the complete sequence of chicken ghrelin gene (submitted to Genbank; accession number AY303688), which consists of 5 exons and 4 introns. As in mice, the first exon of chicken ghrelin gene does not encode any amino acid. (3) Scanning point mutations with denaturing high-performance liquid chromatography (DHPLC) using WAVE DNA Fragment Analysis Systems and confirmed with direct sequencing for polymerase chain reaction (PCR) products, we analysed the single nucleotidepolymorphisms (SNPs) in the entire gene of chicken ghrelin. (4) Results showed that there were 19 SNPs in chicken ghrelin gene, and most of these SNPs were scattered in the 4 introns. In these SNPs, one mutation in exon 5 (A2355G) led to the change of amino acid from glutamine to arginine (Gln 113 Arg): as a result a different ghrelin precursor instead of a mature peptide was produced. In addition, one SNP in 5'UTR (C223G) determined the presence or absence of a potential binding site of transcription factor serum response factor (SRF), which might affect the expression of chicken ghrelin gene. Some of the SNPs detected in the present study could be used in quantitative trait loci (QTL) mapping for growth characters in chickens. (5) Because one SNP is located in a polymorphic site of restriction enzyme PagI of intron 4, it was possible to design a PCR-RFLP procedure and analyse the diversity of 10 chicken populations. Results showed the allelic frequencies of C2100T differ among these breeds, however, no significant difference was observed between imported breeds and Chinese native ones, nor between egg layers and

Endocrine fertility traits, which are defined from progesterone concentration levels in milk, are interesting indicators of dairy cow fertility because they more directly reflect the cows own reproductive physiology than classical fertility traits, which are more biased by farm management decisions. The aim of this study was to detect quantitative trait loci (QTL) for 7 endocrine fertility traits in dairy cows by performing a genome-wide association study with 85k single nucleotidepolymorphisms (SNP), and then fine-map targeted QTL regions, using imputed sequence variants. Two classical fertility traits were also analyzed for QTL with 85k SNP. The association between a SNP and a phenotype was assessed by single-locus regression for each SNP, using a linear mixed model that included a random polygenic effect. A total of 2,447 Holstein Friesian cows with 5,339 lactations with both phenotypes and genotypes were used for association analysis. Heritability estimates ranged from 0.09 to 0.15 for endocrine fertility traits and 0.03 to 0.10 for classical fertility traits. The genome-wide association study identified 17 QTL regions for endocrine fertility traits on Bos taurus autosomes (BTA) 2, 3, 8, 12, 15, 17, 23, and 25. The highest number (5) of QTL regions from the genome-wide association study was identified for the endocrine trait "proportion of samples with luteal activity." Overlapping QTL regions were found between endocrine traits on BTA 2, 3, and 17. For the classical trait calving to first service, 3 QTL regions were identified on BTA 3, 15, and 23, and an overlapping region was identified on BTA 23 with endocrine traits. Fine-mapping target regions for the endocrine traits on BTA 2 and 3 using imputed sequence variants confirmed the QTL from the genome-wide association study, and identified several associated variants that can contribute to an index of markers for genetic improvement of fertility. Several potential candidate genes underlying endocrine

Tumour necrosis factor (TNF), a cytokine mainly produced by macrophages, is associated with a broad spectrum of biological effects, mainly associated with the host defense against microbes. The TNF gene is located on chromosome six within the major histocompatibility complex (MHC). Rheumatoid arthritis (RA) is a systemic autoimmune disease where TNF plays a central role in its etiology and pathogenesis. Written medical evidence of RA can be traced at least as far back as the 17th century, while human paleopathological studies appear to show the presence of RA prior to this period. The fact that RA has experienced an increment both in severity and mortality could be explained by many causes, particularly the crucial role of the immune system. Single-nucleotidepolymorphisms (SNPs) are the most common genetic variations and occur at a frequency of approximately 1 in 1000 bp throughout the genome. The -308 TNF SNP is a mutation that affects the promoter region of the TNF gene. It defines the TNF1 and TNF2 alleles, determining low and high levels of TNF expression, respectively. The presence of the TNF2 allele has also been linked to increased susceptibility to and severity in a variety of autoimmune and inflammatory disorders, including RA, systemic lupus erythematosus, and ankylosing spondylitis. Studies on the functional significance of -308 SNP have detected higher levels of TNF production by cells from TNF2-carrying individuals than cells from TNF1 individuals. This difference does not appear to be due to other genes lying within the MHC region. Since the presence of the TNF2 allele may increase the host's resistance to local infection, by increasing local production of TNF at the infection site, we may suggest that such a mutation has emerged as a selective advantage to carriers of the TNF2 allele. This hypothesis may prove itself by observing the high incidence of tuberculosis and other infectious processes in those patients treated with anti-TNF therapy. Since

We have previously shown that a quantitative-trait locus linked to the OCA2 region of 15q accounts for 74% of variation in human eye color. We conducted additional genotyping to clarify the role of the OCA2 locus in the inheritance of eye color and other pigmentary traits associated with skin-cancer risk in white populations. Fifty-eight synonymous and nonsynonymous exonic single-nucleotidepolymorphisms (SNPs) and tagging SNPs were typed in a collection of 3,839 adolescent twins, their siblings, and their parents. The highest association for blue/nonblue eye color was found with three OCA2 SNPs: rs7495174 T/C, rs6497268 G/T, and rs11855019 T/C (P values of 1.02x10(-61), 1.57x10(-96), and 4.45x10(-54), respectively) in intron 1. These three SNPs are in one major haplotype block, with TGT representing 78.4% of alleles. The TGT/TGT diplotype found in 62.2% of samples was the major genotype seen to modify eye color, with a frequency of 0.905 in blue or green compared with only 0.095 in brown eye color. This genotype was also at highest frequency in subjects with light brown hair and was more frequent in fair and medium skin types, consistent with the TGT haplotype acting as a recessive modifier of lighter pigmentary phenotypes. Homozygotes for rs11855019 C/C were predominantly without freckles and had lower mole counts. The minor population impact of the nonsynonymous coding-region polymorphisms Arg305Trp and Arg419Gln associated with nonblue eyes and the tight linkage of the major TGT haplotype within the intron 1 of OCA2 with blue eye color and lighter hair and skin tones suggest that differences within the 5' proximal regulatory control region of the OCA2 gene alter expression or messenger RNA-transcript levels and may be responsible for these associations. PMID:17236130

Background Single NucleotidePolymorphism (SNP) panels recently developed for the assessment of genetic diversity in wheat are primarily based on elite varieties, mostly those of bread wheat. The usefulness of such SNP panels for studying wheat evolution and domestication has not yet been fully explored and ascertainment bias issues can potentially affect their applicability when studying landraces and tetraploid ancestors of bread wheat. We here evaluate whether population structure and evolutionary history can be assessed in tetraploid landrace wheats using SNP markers previously developed for the analysis of elite cultivars of hexaploid wheat. Results We genotyped more than 100 tetraploid wheat landraces and wild emmer wheat accessions, some of which had previously been screened with SSR markers, for an existing SNP panel and obtained publically available genotypes for the same SNPs for hexaploid wheat varieties and landraces. Results showed that quantification of genetic diversity can be affected by ascertainment bias but that the effects of ascertainment bias can at least partly be alleviated by merging SNPs to haplotypes. Analyses of population structure and genetic differentiation show strong subdivision between the tetraploid wheat subspecies, except for durum and rivet that are not separable. A more detailed population structure of durum landraces could be obtained than with SSR markers. The results also suggest an emmer, rather than durum, ancestry of bread wheat and with gene flow from wild emmer. Conclusions SNP markers developed for elite cultivars show great potential for inferring population structure and can address evolutionary questions in landrace wheat. Issues of marker genome specificity and mapping need, however, to be addressed. Ascertainment bias does not seem to interfere with the ability of a SNP marker system developed for elite bread wheat accessions to detect population structure in other types of wheat. PMID:24885044

A fully integrated and automated microsystem consisting of low-cost, disposable plastic chips for DNA extraction and PCR amplification combined with a reusable glass capillary array electrophoresis chip in a modular-based format was successfully developed for warfarin pharmacogenetic testing. DNA extraction was performed by adopting a filter paper-based method, followed by "in situ" PCR that was carried out directly in the same reaction chamber of the chip without elution. PCR products were then co-injected with sizing standards into separation channels for detection using a novel injection electrode. The entire process was automatically conducted on a custom-made compact control and detection instrument. The limit of detection of the microsystem for the singleplex amplification of amelogenin was determined to be 0.625 ng of standard K562 DNA and 0.3 μL of human whole blood. A two-color multiplex allele-specific PCR assay for detecting the warfarin-related single-nucleotidepolymorphisms (SNPs) 6853 (-1639G>A) and 6484 (1173C>T) in the VKORC1 gene and the *3 SNP (1075A>C) in the CYP2C9 gene was developed and used for validation studies. The fully automated genetic analysis was completed in two hours with a minimum requirement of 0.5 μL of input blood. Samples from patients with different genotypes were all accurately analyzed. In addition, both dried bloodstains and oral swabs were successfully processed by the microsystem with a simple modification to the DNA extraction and amplification chip. The successful development and operation of this microsystem establish the feasibility of rapid warfarin pharmacogenetic testing in routine clinical practice. PMID:26568290

Objective This study aimed to examine single-nucleotidepolymorphisms (SNPs) of seven previously reported obesity genes in East Asians and to analyse their associations and synergistic effects on obesity in the Taiwanese population. Design Cross-sectional study. Setting One medical centre in northern Taiwan. Participants A total of 323 non-obese and 264 obese participants were recruited. The threshold for obesity in this study was a body mass index of ≥27 kg/m2, as defined by the Ministry of Health and Welfare in Taiwan. The study was performed with the approval of the institutional review board of MacKay Memorial Hospital, Taipei, Taiwan (application number 12MMHIS106). Outcome measures We analysed the genotype distributions of seven SNPs localising to the PPARγ2, GNB3, SDC3, ADRB2, FTO, PPARγ and ESR1 genes in obese and non-obese groups and then paired obesity-related SNPs to determine if they have synergistic effects on obesity. Results Analysis of the genotype distributions in obese and non-obese groups revealed only a significant positive correlation between an SNP in rs2282440-syndecan 3 (SDC3) and obesity in the Taiwanese population (p=0.006). In addition, the T/T genotype of SDC3 was significantly associated with a larger waist and hip circumference, higher body fat percentage and lower high-density lipoprotein cholesterol. Moreover, the combination of the rs2282440-SDC3T/T genotype with the rs1801282-peroxisome proliferator-activated receptor-gamma2 gene (PPARγ2) G carrier genotype was strongly associated with obesity (OR=6.77). Conclusions We found that the rs2282440-SDC3T/T genotype is associated with obesity in the Taiwanese population. Furthermore, there is a synergistic effect of the high-risk alleles of the SDC3 and PPARγ2 genes on the obese phenotype in the Taiwanese population. Trial registration number 12MMHIS106; Results. PMID:27515755

VWF is extensively glycosylated with biantennary core fucosylated glycans. Most N-linked and O-linked glycans on VWF are sialylated. FVIII is also glycosylated, with a glycan structure similar to that of VWF. ST3GAL sialyltransferases catalyze the transfer of sialic acids in the α2,3 linkage to termini of N- and O-glycans. This sialic acid modification is critical for VWF synthesis and activity. We analyzed genetic and phenotypic data from the Atherosclerosis Risk in Communities (ARIC) study for the association of single nucleotidepolymorphisms (SNPs) in the ST3GAL4 gene with plasma VWF levels and FVIII activity in 12,117 subjects. We also analyzed ST3GAL4 SNPs found in 2,535 subjects of 26 ethnicities from the 1000 Genomes (1000G) project for ethnic diversity, SNP imputation, and ST3GAL4 haplotypes. We identified 14 and 1,714 ST3GAL4 variants in the ARIC GWAS and 1000G databases respectively, with 46% being ethnically diverse in their allele frequencies. Among the 14 ST3GAL4 SNPs found in ARIC GWAS, the intronic rs2186717, rs7928391, and rs11220465 were associated with VWF levels and with FVIII activity after adjustment for age, BMI, hypertension, diabetes, ever-smoking status, and ABO. This study illustrates the power of next-generation sequencing in the discovery of new genetic variants and a significant ethnic diversity in the ST3GAL4 gene. We discuss potential mechanisms through which these intronic SNPs regulate ST3GAL4 biosynthesis and the activity that affects VWF and FVIII. PMID:27584569

Purpose To explore the effects of single nucleotidepolymorphisms (SNPs) on pancreatic cancer risk and overall survival. Experimental Design The germline DNA of 531 pancreatic cancer cases and 305 healthy controls from a hospital-based study was genotyped at SNPs previously reported to be associated with pancreatic cancer risk or clinical outcome. We analyzed putative risk SNPs for replication of their reported effects on risk and tested for novel effects on overall survival (OS). Similarly, we analyzed putative survival-associated SNPs for replication of their reported effects on OS and tested for novel effects on risk. Lastly, we performed a genome-wide association study of OS using a subset of 252 cases, with two subsequent validation sets of 261 and 572 patients, respectively. Results Among seven risk SNPs analyzed, two (rs505922, rs9543325) were associated with risk (p<0.05). Among 24 survival-associated SNPs analyzed, one (rs9350) was associated with OS (p<0.05). No putative risk SNPs or putative survival-associated SNPs were found to be associated with OS or risk, respectively. Further, our GWAS identified a novel SNP (rs1482426, combined stage 1 and 2 p = 1.7 ×10−6, per-allele HR = 1.74, 95% CI 1.38–2.18) to be putatively associated with OS. Conclusions The effects of SNPs on pancreatic cancer risk and overall survival were replicated in our study, though further work is necessary to understand the functional mechanisms underlying these effects. More importantly, the putative association with OS identified by GWAS suggests that GWAS may be useful in identifying SNPs associated with clinical outcome in pancreatic cancer. PMID:22665904

Acute myeloid leukemia (AML) is a group of clonal diseases, resulting from two classes of mutation. Investigation for additional abnormalities associated with a well-recognized subtype, core-binding factor AML (CBF-AML) can provide further understanding and discrimination to this special group of leukemia. In order to better define genetic alterations in CBF-AML and identify possible cooperating lesions, a single-nucleotidepolymorphism-array (SNP-array) analysis was performed, combined to KIT mutation screening, in a set of cases. Validation of SNP-array results was done by array comparative genomic hybridization and FISH. Fifteen cases were analyzed. Three cases had microscopic lesions better delineated by arrays. One case had +22 not identified by arrays. Submicroscopic abnormalities were mostly non-recurrent between samples. Of relevance, four regions were more frequently affected: 4q28, 9p11, 16q22.1, and 16q23. One case had an uncovered unbalanced inv(16) due to submicroscopic deletion of 5´MYH11 and 3´CBFB. Telomeric and large copy number neutral loss of heterozygosity (CNN-LOH) regions (>25 Mb), likely representing uniparental disomy, were detected in four out of fifteen cases. Only three cases had mutation